CriticalCVE-2026-42055

    NGINX ngx_http_proxy_v2_module and ngx_http_grpc_module vulnerability (CVE-2026-42055)

    Published Last modified Sources: Red Hat, SingCERT, Debian LTS, Msrc Update Guide, F5, CVE.org, OSV, Debian, Ubuntu, BSI

    What is affected, what to do

    A flaw was found in NGINX. When NGINX is configured to proxy HTTP/2 traffic using the ngx_http_proxy_v2_module or ngx_http_grpc_module with specific settings, a remote, unauthenticated attacker can send specially crafted large headers.

    An exploit is publicly available. Update F5 NGINX Open Source to version 1.31.2, F5 NGINX Open Source to version 1.30.3, F5 NGINX Plus to version 37.0.2.1.

    Affected
    • F5 NGINX Open Source lt 1.13.10..1.31.2
    • F5 NGINX Open Source lt 1.30.2..1.30.3
    • F5 NGINX Plus lt 37.0..37.0.2.1
    • F5 NGINX Plus gte R36..*
    Fixed in
    • F5 NGINX Open Source 1.31.2
    • F5 NGINX Open Source 1.30.3
    • F5 NGINX Plus 37.0.2.1

    Not sure whether and how you are affected? Ask a question about this vulnerability

    Metrics

    9.2

    Priority

    XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.

    Source: NVD, CVSS v4

    8.1

    CVSS v3

    Severity High on the scale from 0 to 10.

    Source: Red Hat, SingCERT, Debian LTS, Msrc Update Guide, F5, CVE.org, OSV, Debian, Ubuntu, BSI

    6.5 %

    EPSS score

    Moderate — model estimates 1-10% exploitation likelihood.

    Source: FIRST EPSS, percentile 93.8

    Show all metrics
    Severity
    Critical
    Priority (0–325)

    The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first?

    Read in glossary
    135.43 Methodology
    Exploit maturity

    An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack.

    Read in glossary
    PoC (publicly reported)
    XIEM Effective CVSS

    XIEM® is the tiered managed-security operating model from NEOSEC and a registered trademark of NEOSEC GmbH. It extends classic SIEM — the central collection, normalisation and correlation of security-relevant events — with endpoint forensics, network visibility and deception technology, and consolidates them into three building tiers: Sentry, Orchestrate and Command.

    Read in glossary
    9.2 Methodology
    CVSS v3

    CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.

    Read in glossary
    8.1
    CVSS v4

    CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.

    Read in glossary
    9.2
    EPSS score

    The EPSS score is the absolute model output for an individual vulnerability: the estimated probability of real-world exploitation within the next 30 days, expressed as a value between 0 and 1 (i.e. 0 % to 100 %). A score of 0.42 means „the model estimates a 42 % chance of real-world exploitation within 30 days“.

    Read in glossary
    6.5 %
    Moderate — model estimates 1-10% exploitation likelihood.
    EPSS percentile

    The EPSS percentile is the relative position of a vulnerability within all EPSS-scored CVEs, expressed as a value between 0 and 1. A percentile of 0.90 means „this CVE has a higher EPSS score than 90 % of all other scored CVEs“. Unlike the EPSS score, it is not a probability — but a positioning within a ranking.

    Read in glossary
    93.8
    Critical — this CVE ranks in the top fifth of all CVEs scored today (rank ≥ 80%).
    KEV status

    The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.

    Read in glossary
    —
    Published
    CISA assessment (SSVC)
    Exploitation: none known · not automatable · Technical impact: total
    Source: CISA Vulnrichment, as of 17 June 2026
    CWE

    CWE is a catalogue of typical weakness types in software and hardware — such as flawed input validation, unsafe memory handling or poor authentication. Where a CVE names a concrete vulnerability in a concrete product, a CWE describes the underlying class of defect.

    Read in glossary
    CWE-122

    Detection rules

    No NEOSEC detection rule is available for this vulnerability yet.

    Classification under NIS2 and CRA

    Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.

    NIS2

    NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management.

    Read in glossary
    High technical severity: assess and remediate the vulnerability in vulnerability handling under Art. 21(2)(e) NIS2 and document the decision.
    CRA

    The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates.

    Read in glossary
    From 11.12.2027, Annex I Part II CRA requires manufacturers of affected products with digital elements to handle vulnerabilities without delay and provide security updates.
    ISO/IEC 27001

    ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security.

    Read in glossary
    Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.

    Description

    A flaw was found in NGINX. When NGINX is configured to proxy HTTP/2 traffic using the ngx_http_proxy_v2_module or ngx_http_grpc_module with specific settings, a remote, unauthenticated attacker can send specially crafted large headers. This can trigger a heap-based buffer overflow, leading to a restart of the NGINX worker process and a Denial of Service (DoS). Under certain conditions, such as when Address Space Layout Randomization (ASLR) is disabled or bypassed, this vulnerability could also allow for arbitrary code execution.

    Source: redhat_csaf, CSA/SingCERT, Debian LTS Advisories, Microsoft Security Update Guide, f5_askf5, cvelistv5, OSV (Open Source Vulnerabilities), Debian Security Advisories, NVD (NIST), Ubuntu Security Notices, BSI WID Portal, BSI CSAF

    Affected products

    The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.

    Affected products
    Affected versionsFixed in
    F5NGINX Open Source
    • 1.13.10 – < 1.31.2
    • 1.30.2 – < 1.30.3
    • 1.31.2
    • 1.30.3
    F5NGINX Plus
    • ≥ R36
    • 37.0 – < 37.0.2.1
    • —
    • 37.0.2.1
    f5dos
    • 4.9.0
    • 4.3.0 – ≤ 4.7.0
    • —
    • —
    f5nginx_gateway_fabric
    • 1.3.0 – ≤ 1.6.2
    • 2.0.0 – ≤ 2.6.3
    • —
    • —
    f5nginx_ingress_controller
    • 5.0.0 – ≤ 5.5.0
    • 3.5.0 – ≤ 3.7.2
    • 4.0.0 – ≤ 4.0.1
    • —
    • —
    • —
    f5nginx_instance_manager
    • 2.17.0 – ≤ 2.22.0
    • —
    f5nginx_open_source
    • 1.31.0 – ≤ 1.31.1
    • 1.0.0 – ≤ 1.30.2
    • —
    • —
    f5nginx_plus
    • r36
    • 37.0.0.1 – < 37.0.2.1
    • r33 – < r36
    • —
    • 37.0.2.1
    • r36
    f5waf
    • 4.10.0 – ≤ 4.16.0
    • 5.9.0 – ≤ 5.13.1
    • 5.2.0 – ≤ 5.8.0
    • —
    • —
    • —
    redhatdiscovery
    • —
    • —
    redhathardened_images
    • —
    • —
    redhatupdate_infrastructure
    • 5.0 – < 5.2
    • 5.2
    NGINXNGINX
    • Ingress Controller
    • Instance Manager
    • App Protect WAF
    • App Protect DoS
    • —
    • —
    • —
    • —
    NGINXNGINX Gateway Fabric
    • < 2.6.4
    • 2.6.4
    NGINXNGINX Open Source
    • < 1.30.3
    • < 1.31.2
    • 1.30.3
    • 1.31.2
    NGINXNGINX Plus
    • <R36 P6
    • < 37.0.2.1
    • —
    • 37.0.2.1

    Vendors and products

    Affected operating systems

    Affected operating systems
    Linuxredhatenterprise_linux10.0
    Linuxredhatenterprise_linux8.0
    Linuxredhatenterprise_linux9.0
    Linuxdebiannginxbookworm
    Linuxdebiannginxbullseye
    Linuxdebiannginxtrixie

    Weakness classes (CWE)

    • CWE-122Heap-based Buffer Overflow

      Variant

      A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().

      Entry at MITRE CWE-122

    Public exploit references

    Publicly reported proof-of-concepts, exploit modules and detection templates for this vulnerability. NEOSEC links to the original sources only and does not provide any exploit code.

    Public exploit references
    PoC-in-GitHub (nomi-sec)CVE-2026-42055 (opens in a new tab)github.comPoC (publicly reported)reported, not verified

    References & sources

    Changes to this CVE

    Who changed this CVE and when: NVD (analysis, affected products, CVSS), the CVE publisher (CNA) and additional providers such as CISA (ADP).

    1. Record modifiedf5.com

      Show 3 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Referenceadded
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      https://my.f5.com/manage/s/article/K000161584
      Referenceremoved
      https://my.f5.com/manage/s/article/K000161584
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      Reference typeremoved
      https://my.f5.com/manage/s/article/K000161584 Types: Vendor Advisory
      —

      Source identifier: f5sirt@f5.com

    2. Record modifiedRed Hat ADP

      Show 36 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Affected versions (publisher)added
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      Affected value modified. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/42xxx/CVE-2026-42055.json">CVE-2026-42055</a>
      Referenceadded
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      https://access.redhat.com/errata/RHSA-2026:27197
      Referenceadded
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      https://access.redhat.com/errata/RHSA-2026:36331
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      https://access.redhat.com/errata/RHSA-2026:36364
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      https://access.redhat.com/errata/RHSA-2026:36618
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      https://access.redhat.com/errata/RHSA-2026:36639
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      https://access.redhat.com/errata/RHSA-2026:38847
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      https://access.redhat.com/errata/RHSA-2026:44481
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      https://access.redhat.com/errata/RHSA-2026:46836
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      https://access.redhat.com/errata/RHSA-2026:58981
      Referenceadded
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      https://access.redhat.com/security/cve/CVE-2026-42055
      Referenceadded
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      https://bugzilla.redhat.com/show_bug.cgi?id=2489866
      Referenceadded
      —
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-42055.json
      Referenceremoved
      https://access.redhat.com/errata/RHSA-2026:27197
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      Referenceremoved
      https://access.redhat.com/errata/RHSA-2026:36331
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      Referenceremoved
      https://access.redhat.com/errata/RHSA-2026:36364
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      Referenceremoved
      https://access.redhat.com/errata/RHSA-2026:36618
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      Referenceremoved
      https://access.redhat.com/errata/RHSA-2026:36639
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      Referenceremoved
      https://access.redhat.com/errata/RHSA-2026:38847
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      Referenceremoved
      https://access.redhat.com/errata/RHSA-2026:44481
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      Referenceremoved
      https://access.redhat.com/errata/RHSA-2026:46836
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      Referenceremoved
      https://access.redhat.com/errata/RHSA-2026:58981
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      Referenceremoved
      https://access.redhat.com/security/cve/CVE-2026-42055
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      Referenceremoved
      https://bugzilla.redhat.com/show_bug.cgi?id=2489866
      —
      Referenceremoved
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-42055.json
      —
      Reference typeremoved
      https://access.redhat.com/errata/RHSA-2026:27197 Types: Third Party Advisory
      —
      Reference typeremoved
      https://access.redhat.com/errata/RHSA-2026:36331 Types: Third Party Advisory
      —
      Reference typeremoved
      https://access.redhat.com/errata/RHSA-2026:36364 Types: Third Party Advisory
      —
      Reference typeremoved
      https://access.redhat.com/errata/RHSA-2026:36618 Types: Third Party Advisory
      —
      Reference typeremoved
      https://access.redhat.com/errata/RHSA-2026:36639 Types: Third Party Advisory
      —
      Reference typeremoved
      https://access.redhat.com/errata/RHSA-2026:38847 Types: Third Party Advisory
      —
      Reference typeremoved
      https://access.redhat.com/errata/RHSA-2026:44481 Types: Third Party Advisory
      —
      Reference typeremoved
      https://access.redhat.com/errata/RHSA-2026:46836 Types: Third Party Advisory
      —
      Reference typeremoved
      https://access.redhat.com/security/cve/CVE-2026-42055 Types: Third Party Advisory
      —
      Reference typeremoved
      https://bugzilla.redhat.com/show_bug.cgi?id=2489866 Types: Issue Tracking, Third Party Advisory
      —
      Reference typeremoved
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-42055.json Types: Third Party Advisory
      —

      Source identifier: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

    3. Record modifiedRed Hat ADP

      Show 2 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Referenceadded
      —
      https://access.redhat.com/errata/RHSA-2026:58981
      Affected versions (publisher)changed
      Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9 (+10)
      Red Hat Openshift Data Foundation 4, Red Hat Discovery 2, Red Hat Update Infrastructure 5 (+7)

      Source identifier: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

    4. Reanalysis by NVDNVD

      Newly listed as affected:
      Product mapping changed:
      Show 3 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Product configurationadded
      —
      OR *cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:* *cpe:2.3:a:redhat:discovery:-:*:*:*:*:*:*:* *cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:* *cpe:2.3:o:redhat:enterprise_linux:10.0:*:*:*:*:*:*:* *cpe:2.3:a:redhat:hardened_images:-:*:*:*:*:*:*:* *cpe:2.3:a:redhat:update_infrastructure:*:*:*:*:*:*:*:* versions from (including) 5.0 up to (excluding) 5.2
      Product configurationchanged
      OR *cpe:2.3:a:f5:nginx_plus:r30:-:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r31:p1:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r30:p2:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r31:-:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r32:-:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r30:p1:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r32:p1:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r32:p2:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r33:-:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r33:p1:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r33:p2:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r34:-:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r34:p1:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r32:p3:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r33:p3:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r34:p2:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r35:-:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r36:-:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r36:p1:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r35:p1:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r36:p2:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r32:p4:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_gateway_fabric:*:*:*:*:*:*:*:* versions from (including) 1.3.0 up to (including) 1.6.2 *cpe:2.3:a:f5:nginx_ingress_controller:*:*:*:*:*:*:*:* versions from (including) 3.5.0 up to (including) 3.7.2 *cpe:2.3:a:f5:dos:*:*:*:*:*:nginx:*:* versions from (including) 4.3.0 up to (including) 4.7.0 *cpe:2.3:a:f5:dos:4.9.0:*:*:*:*:nginx:*:* *cpe:2.3:a:f5:nginx_instance_manager:*:*:*:*:*:*:*:* versions from (including) 2.17.0 up to (including) 2.22.0 *cpe:2.3:a:f5:nginx_plus:*:*:*:*:*:*:*:* versions from (including) 37.0.0 up to (including) 37.0.1 *cpe:2.3:a:f5:waf:*:*:*:*:*:nginx:*:* versions from (including) 4.10.0 up to (including) 4.16.0 *cpe:2.3:a:f5:waf:*:*:*:*:*:nginx:*:* versions from (including) 5.2.0 up to (including) 5.8.0 *cpe:2.3:a:f5:waf:*:*:*:*:*:nginx:*:* versions from (including) 5.9.0 up to (including) 5.13.1 *cpe:2.3:a:f5:nginx_gateway_fabric:*:*:*:*:*:*:*:* versions from (including) 2.0.0 up to (excluding) 2.6.4 *cpe:2.3:a:f5:nginx_ingress_controller:*:*:*:*:*:*:*:* versions from (including) 5.0.0 up to (excluding) 5.5.1 *cpe:2.3:a:f5:nginx_ingress_controller:4.0.0:*:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_ingress_controller:4.0.1:*:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_open_source:*:*:*:*:*:*:*:* versions from (including) 1.30.0 up to (excluding) 1.30.3 *cpe:2.3:a:f5:nginx_open_source:1.31.1:*:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r3:*:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r31:p2:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r31:p3:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r36:p3:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r36:p4:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r36:p5:*:*:*:*:*:* *cpe:2.3:a:f5:waf:4.8.1:*:*:*:*:nginx:*:*
      OR *cpe:2.3:a:f5:nginx_gateway_fabric:*:*:*:*:*:*:*:* versions from (including) 1.3.0 up to (including) 1.6.2 *cpe:2.3:a:f5:dos:*:*:*:*:*:nginx:*:* versions from (including) 4.3.0 up to (including) 4.7.0 *cpe:2.3:a:f5:dos:4.9.0:*:*:*:*:nginx:*:* *cpe:2.3:a:f5:nginx_gateway_fabric:*:*:*:*:*:*:*:* versions from (including) 2.0.0 up to (including) 2.6.3 *cpe:2.3:a:f5:nginx_instance_manager:*:*:*:*:*:*:*:* versions from (including) 2.17.0 up to (including) 2.22.0 *cpe:2.3:a:f5:nginx_open_source:*:*:*:*:*:*:*:* versions from (including) 1.0.0 up to (including) 1.30.2 *cpe:2.3:a:f5:nginx_open_source:*:*:*:*:*:*:*:* versions from (including) 1.31.0 up to (including) 1.31.1 *cpe:2.3:a:f5:waf:*:*:*:*:*:nginx:*:* versions from (including) 4.10.0 up to (including) 4.16.0 *cpe:2.3:a:f5:waf:*:*:*:*:*:nginx:*:* versions from (including) 5.2.0 up to (including) 5.8.0 *cpe:2.3:a:f5:waf:*:*:*:*:*:nginx:*:* versions from (including) 5.9.0 up to (including) 5.13.1 *cpe:2.3:a:f5:nginx_ingress_controller:*:*:*:*:continuous_releases:*:*:* versions from (including) 3.5.0 up to (including) 3.7.2 *cpe:2.3:a:f5:nginx_plus:*:*:*:*:continuous_releases:*:*:* versions from (including) r33 up to (excluding) r36 *cpe:2.3:a:f5:nginx_plus:r36:-:*:*:continuous_releases:*:*:* *cpe:2.3:a:f5:nginx_plus:r36:p1:*:*:continuous_releases:*:*:* *cpe:2.3:a:f5:nginx_plus:r36:p2:*:*:continuous_releases:*:*:* *cpe:2.3:a:f5:nginx_plus:r36:p3:*:*:continuous_releases:*:*:* *cpe:2.3:a:f5:nginx_plus:r36:p4:*:*:continuous_releases:*:*:* *cpe:2.3:a:f5:nginx_ingress_controller:*:*:*:*:continuous_releases:*:*:* versions from (including) 4.0.0 up to (including) 4.0.1 *cpe:2.3:a:f5:nginx_plus:*:*:*:*:long-term_support:*:*:* versions from (including) 37.0.0.1 up to (excluding) 37.0.2.1 *cpe:2.3:a:f5:nginx_plus:r36:p5:*:*:continuous_releases:*:*:* *cpe:2.3:a:f5:nginx_ingress_controller:*:*:*:*:continuous_releases:*:*:* versions from (including) 5.0.0 up to (including) 5.5.0
      Reference typechanged
      redhat-SADP: https://bugzilla.redhat.com/show_bug.cgi?id=2489866 Types: Third Party Advisory
      redhat-SADP: https://bugzilla.redhat.com/show_bug.cgi?id=2489866 Types: Issue Tracking, Third Party Advisory

      Source identifier: nvd@nist.gov

    5. NVD analysis modifiedNVD

      Product mapping changed:
      Show 8 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Product configurationchanged
      OR *cpe:2.3:a:f5:nginx_plus:r30:-:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r31:p1:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r30:p2:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r31:-:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r32:-:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r30:p1:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r32:p1:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r32:p2:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r33:-:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r33:p1:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r33:p2:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r34:-:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r34:p1:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r32:p3:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r33:p3:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r34:p2:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r35:-:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r36:-:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r36:p1:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r35:p1:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r36:p2:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r32:p4:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_app_protect_dos:*:*:*:*:*:*:*:* versions from (including) 4.3.0 up to (including) 4.7.0 *cpe:2.3:a:f5:nginx_gateway_fabric:*:*:*:*:*:*:*:* versions from (including) 1.3.0 up to (including) 1.6.2 *cpe:2.3:a:f5:nginx_ingress_controller:*:*:*:*:*:*:*:* versions from (including) 3.5.0 up to (including) 3.7.2 *cpe:2.3:a:f5:dos:4.9.0:*:*:*:*:nginx:*:* *cpe:2.3:a:f5:nginx_instance_manager:*:*:*:*:*:*:*:* versions from (including) 2.17.0 up to (including) 2.22.0 *cpe:2.3:a:f5:nginx_plus:*:*:*:*:*:*:*:* versions from (including) 37.0.0 up to (including) 37.0.1 *cpe:2.3:a:f5:waf:*:*:*:*:*:nginx:*:* versions from (including) 5.9.0 up to (including) 5.13.1 *cpe:2.3:a:f5:nginx_gateway_fabric:*:*:*:*:*:*:*:* versions from (including) 2.0.0 up to (excluding) 2.6.4 *cpe:2.3:a:f5:nginx_ingress_controller:*:*:*:*:*:*:*:* versions from (including) 5.0.0 up to (excluding) 5.5.1 *cpe:2.3:a:f5:nginx_ingress_controller:4.0.0:*:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_ingress_controller:4.0.1:*:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_app_protect_waf:*:*:*:*:*:*:*:* versions from (including) 4.10.0 up to (including) 4.16.0 *cpe:2.3:a:f5:nginx_app_protect_waf:*:*:*:*:*:*:*:* versions from (including) 5.2.0 up to (including) 5.8.0 *cpe:2.3:a:f5:nginx_open_source:*:*:*:*:*:*:*:* versions from (including) 1.30.0 up to (excluding) 1.30.3 *cpe:2.3:a:f5:nginx_open_source:1.31.1:*:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r3:*:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r31:p2:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r31:p3:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r36:p3:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r36:p4:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r36:p5:*:*:*:*:*:* *cpe:2.3:a:f5:waf:4.8.1:*:*:*:*:nginx:*:*
      OR *cpe:2.3:a:f5:nginx_plus:r30:-:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r31:p1:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r30:p2:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r31:-:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r32:-:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r30:p1:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r32:p1:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r32:p2:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r33:-:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r33:p1:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r33:p2:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r34:-:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r34:p1:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r32:p3:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r33:p3:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r34:p2:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r35:-:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r36:-:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r36:p1:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r35:p1:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r36:p2:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r32:p4:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_gateway_fabric:*:*:*:*:*:*:*:* versions from (including) 1.3.0 up to (including) 1.6.2 *cpe:2.3:a:f5:nginx_ingress_controller:*:*:*:*:*:*:*:* versions from (including) 3.5.0 up to (including) 3.7.2 *cpe:2.3:a:f5:dos:*:*:*:*:*:nginx:*:* versions from (including) 4.3.0 up to (including) 4.7.0 *cpe:2.3:a:f5:dos:4.9.0:*:*:*:*:nginx:*:* *cpe:2.3:a:f5:nginx_instance_manager:*:*:*:*:*:*:*:* versions from (including) 2.17.0 up to (including) 2.22.0 *cpe:2.3:a:f5:nginx_plus:*:*:*:*:*:*:*:* versions from (including) 37.0.0 up to (including) 37.0.1 *cpe:2.3:a:f5:waf:*:*:*:*:*:nginx:*:* versions from (including) 4.10.0 up to (including) 4.16.0 *cpe:2.3:a:f5:waf:*:*:*:*:*:nginx:*:* versions from (including) 5.2.0 up to (including) 5.8.0 *cpe:2.3:a:f5:waf:*:*:*:*:*:nginx:*:* versions from (including) 5.9.0 up to (including) 5.13.1 *cpe:2.3:a:f5:nginx_gateway_fabric:*:*:*:*:*:*:*:* versions from (including) 2.0.0 up to (excluding) 2.6.4 *cpe:2.3:a:f5:nginx_ingress_controller:*:*:*:*:*:*:*:* versions from (including) 5.0.0 up to (excluding) 5.5.1 *cpe:2.3:a:f5:nginx_ingress_controller:4.0.0:*:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_ingress_controller:4.0.1:*:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_open_source:*:*:*:*:*:*:*:* versions from (including) 1.30.0 up to (excluding) 1.30.3 *cpe:2.3:a:f5:nginx_open_source:1.31.1:*:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r3:*:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r31:p2:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r31:p3:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r36:p3:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r36:p4:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r36:p5:*:*:*:*:*:* *cpe:2.3:a:f5:waf:4.8.1:*:*:*:*:nginx:*:*
      Reference typeadded
      —
      redhat-SADP: https://access.redhat.com/errata/RHSA-2026:36331 Types: Third Party Advisory
      Reference typeadded
      —
      redhat-SADP: https://access.redhat.com/errata/RHSA-2026:36364 Types: Third Party Advisory
      Reference typeadded
      —
      redhat-SADP: https://access.redhat.com/errata/RHSA-2026:36618 Types: Third Party Advisory
      Reference typeadded
      —
      redhat-SADP: https://access.redhat.com/errata/RHSA-2026:36639 Types: Third Party Advisory
      Reference typeadded
      —
      redhat-SADP: https://access.redhat.com/errata/RHSA-2026:38847 Types: Third Party Advisory
      Reference typeadded
      —
      redhat-SADP: https://access.redhat.com/errata/RHSA-2026:44481 Types: Third Party Advisory
      Reference typeadded
      —
      redhat-SADP: https://access.redhat.com/errata/RHSA-2026:46836 Types: Third Party Advisory

      Source identifier: nvd@nist.gov

    Show 6 older changes

    1. Record modifiedRed Hat ADP

      Show 2 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Referenceadded
      —
      https://access.redhat.com/errata/RHSA-2026:46836
      Affected versions (publisher)changed
      Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9 (+9)
      Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9 (+10)

      Source identifier: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

    2. Record modifiedRed Hat ADP

      Show 2 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Referenceadded
      —
      https://access.redhat.com/errata/RHSA-2026:44481
      Affected versions (publisher)changed
      Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9 (+6)
      Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9 (+9)

      Source identifier: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

    3. Record modifiedRed Hat ADP

      Show 2 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Referenceadded
      —
      https://access.redhat.com/errata/RHSA-2026:36639
      Affected versions (publisher)changed
      Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux AppStream (v. 9), Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) (+5)
      Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux AppStream (v. 9), Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) (+4)

      Source identifier: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

    4. Initial analysis by NVDNVD

      Newly listed as affected:

      Weakness type: CWE-787

      Show 7 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Weakness type (CWE)added
      —
      CWE-787
      Product configurationadded
      —
      OR *cpe:2.3:a:f5:nginx_plus:r30:-:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r31:p1:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r30:p2:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r31:-:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r32:-:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r30:p1:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r32:p1:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r32:p2:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r33:-:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r33:p1:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r33:p2:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r34:-:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r34:p1:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r32:p3:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r33:p3:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r34:p2:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r35:-:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r36:-:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r36:p1:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r35:p1:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r36:p2:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r32:p4:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_app_protect_dos:*:*:*:*:*:*:*:* versions from (including) 4.3.0 up to (including) 4.7.0 *cpe:2.3:a:f5:nginx_gateway_fabric:*:*:*:*:*:*:*:* versions from (including) 1.3.0 up to (including) 1.6.2 *cpe:2.3:a:f5:nginx_ingress_controller:*:*:*:*:*:*:*:* versions from (including) 3.5.0 up to (including) 3.7.2 *cpe:2.3:a:f5:dos:4.9.0:*:*:*:*:nginx:*:* *cpe:2.3:a:f5:nginx_instance_manager:*:*:*:*:*:*:*:* versions from (including) 2.17.0 up to (including) 2.22.0 *cpe:2.3:a:f5:nginx_plus:*:*:*:*:*:*:*:* versions from (including) 37.0.0 up to (including) 37.0.1 *cpe:2.3:a:f5:waf:*:*:*:*:*:nginx:*:* versions from (including) 5.9.0 up to (including) 5.13.1 *cpe:2.3:a:f5:nginx_gateway_fabric:*:*:*:*:*:*:*:* versions from (including) 2.0.0 up to (excluding) 2.6.4 *cpe:2.3:a:f5:nginx_ingress_controller:*:*:*:*:*:*:*:* versions from (including) 5.0.0 up to (excluding) 5.5.1 *cpe:2.3:a:f5:nginx_ingress_controller:4.0.0:*:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_ingress_controller:4.0.1:*:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_app_protect_waf:*:*:*:*:*:*:*:* versions from (including) 4.10.0 up to (including) 4.16.0 *cpe:2.3:a:f5:nginx_app_protect_waf:*:*:*:*:*:*:*:* versions from (including) 5.2.0 up to (including) 5.8.0 *cpe:2.3:a:f5:nginx_open_source:*:*:*:*:*:*:*:* versions from (including) 1.30.0 up to (excluding) 1.30.3 *cpe:2.3:a:f5:nginx_open_source:1.31.1:*:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r3:*:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r31:p2:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r31:p3:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r36:p3:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r36:p4:*:*:*:*:*:* *cpe:2.3:a:f5:nginx_plus:r36:p5:*:*:*:*:*:* *cpe:2.3:a:f5:waf:4.8.1:*:*:*:*:nginx:*:*
      Reference typeadded
      —
      F5 Networks: https://my.f5.com/manage/s/article/K000161584 Types: Vendor Advisory
      Reference typeadded
      —
      redhat-SADP: https://access.redhat.com/errata/RHSA-2026:27197 Types: Third Party Advisory
      Reference typeadded
      —
      redhat-SADP: https://access.redhat.com/security/cve/CVE-2026-42055 Types: Third Party Advisory
      Reference typeadded
      —
      redhat-SADP: https://bugzilla.redhat.com/show_bug.cgi?id=2489866 Types: Third Party Advisory
      Reference typeadded
      —
      redhat-SADP: https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-42055.json Types: Third Party Advisory

      Source identifier: nvd@nist.gov

    5. Record modifiedCISA ADP

      CISA assessment (SSVC): exploitation: none known, automatable: no

      Show the original change
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      SSVC assessmentadded
      —
      {"id":"CVE-2026-42055","role":"CISA Coordinator","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"total"}],"version":"2.0.3","timestamp":"2026-06-17T15:43:07.643763Z"}

      Source identifier: 134c704f-9b21-4f2e-91b3-4a467353bcc0

    6. Receivedf5.com

      CVSS V4.0: AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

      CVSS V3.1: AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

      Weakness type: CWE-122

      Description added or changed

      Show 6 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Affected versions (publisher)added
      —
      NGINX Open Source, NGINX Plus
      Descriptionadded
      —
      NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_proxy_v2_module and ngx_http_grpc_module modules. This vulnerability exists when the proxy_http_version to 2 or grpc_pass directives are used to proxy HTTP/2 traffic, the ignore_invalid_headers directive is set to off, and the large_client_header_buffers directive size is larger than 2 megabytes. A remote, unauthenticated attacker, along with conditions beyond their control, could send large headers while creating an upstream request. This may cause a heap-based buffer overflow in the NGINX worker process leading to a restart. Additionally, attackers can execute code on systems with Address Space Layout Randomization (ASLR) disabled or when the attacker can bypass ASLR. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
      CVSSadded
      —
      AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
      CVSSadded
      —
      AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
      Weakness type (CWE)added
      —
      CWE-122
      Referenceadded
      —
      https://my.f5.com/manage/s/article/K000161584

      Source identifier: f5sirt@f5.com

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    <a href="https://intel.neosec.eu/en/cve/CVE-2026-42055"><img src="https://intel.neosec.eu/badge/cve/CVE-2026-42055.svg?lang=en" alt="CVE-2026-42055 – NEOSEC Intel" height="20"></a>