HighCVE-2026-108082

    Symfony: ReDoS in HeaderUtils::split() Reachable Through the Cache-Control Request Header (CVE-2026-108082)

    Published Last modified Sources: OSV, CVE.org, Hersteller, BSI

    What is affected, what to do

    Update open source Snipe-IT to version 8.8.1.

    Affected
    • open source Snipe-IT < *..8.8.1
    Fixed in
    • open source Snipe-IT 8.8.1

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

    Metrics

    8.7

    Priority

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

    Source: Vendor (CNA), CVSS v4

    8.7

    CVSS v4

    Severity High on the scale from 0 to 10.

    Source: OSV, CVE.org, Hersteller, BSI

    0.5 %

    EPSS score

    Low — model estimates < 1% exploitation likelihood.

    Source: FIRST EPSS, percentile 41.4

    Show all metrics
    Severity
    High
    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
    87.24 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
    no public PoC known
    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
    8.7 Methodology
    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
    8.7
    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
    0.5 %
    Low — model estimates < 1% 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
    41.4
    High — this CVE ranks above the median of all CVEs scored today (rank ≥ 36%).
    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 · automatable · Technical impact: partial
    Source: CISA Vulnrichment, as of 15 October 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-1333

    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

    Description

    HeaderUtils::split() parsed header values with a pattern whose token alternative also matched whitespace, followed by a (?<!\s) lookbehind. A run of whitespace placed before a separator could be divided among the iterations of the enclosing repetition in exponentially many ways, and the engine tried all of them before settling. HeaderBag calls it for the Cache-Control header whenever a Request is built, so any application handling HTTP requests is reachable, with no authentication.

    A single request carrying such a header costs close to a second of CPU (813 ms for a run of 17 spaces in an 8 KB header on PHP 8.5, doubling with each extra space). From 18 spaces on, preg_match_all() gives up at pcre.backtrack_limit and split() returns an empty array, so every directive of the header is silently dropped.

    Resolution

    The pattern now consumes whitespace only when more of the value follows it, so a value can no longer end on whitespace, nothing has to be given back, and every quantifier is possessive. The first release of this fix broke splitting on a whitespace separator: HeaderUtils::split('foo bar', ' ') returned a single value in 6.4.46 to 6.4.47, 7.4.19 to 7.4.20 and 8.1.7 to 8.1.8. Whitespace characters used as separators are now left out of the whitespace branch, which 6.4.48, 7.4.21 and 8.1.9 contain.

    The patches for this issue are available here for branch 5.4 (and forward-ported to 6.4, 7.4, 8.1 and 8.2).

    Credits

    Symfony would like to thank r3verii for reporting the issue and Nicolas Grekas for providing the fix.

    Symfony would also like to thank Bruno Dias from Checkmarx for his help getting a CVE assigned.

    Source: OSV (Open Source Vulnerabilities), cvelistv5, NVD (NIST), GitHub Security Advisories, BSI CSAF, BSI WID Portal

    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
    sensiolabssymfony
    • —
    • —
    Open SourceSnipe-IT
    • < 8.8.1
    • 8.8.1
    composersymfony/http-foundation
    • >= 6.0.1, < 6.4.46
    • >= 8.0.0, < 8.1.7
    • >= 7.0.0, < 7.4.19
    • >= 4.1.0, < 5.4.54
    • 6.4.46
    • 8.1.7
    • 7.4.19
    • 5.4.54
    composersymfony/symfony
    • >= 6.0.1, < 6.4.46
    • >= 7.0.0, < 7.4.19
    • >= 8.0.0, < 8.1.7
    • >= 4.1.0, < 5.4.54
    • 6.4.46
    • 7.4.19
    • 8.1.7
    • 5.4.54
    packagistsymfony/http-foundation
    • v5.4.12
    • v4.4.6
    • v5.3.0-BETA2
    • v5.1.11
    • v4.1.5
    • v5.3.7
    • v6.2.2
    • v4.4.33
    • v6.4.44
    • v8.0.6
    • v7.4.15
    • v8.0.14
    • v5.1.0-RC2
    • v4.2.10
    • v6.3.1
    • v4.1.7
    • v6.4.2
    • 4.1.0
    • v5.3.3
    • v6.3.0-BETA3
    • v4.4.0-BETA2
    • v4.2.12
    • v7.4.7
    • v6.1.7
    • v5.2.7
    • v4.4.3
    • v7.3.9
    • v5.4.32
    • v5.0.7
    • v4.4.41
    • v5.4.6
    • v6.4.21
    • v5.4.2
    • v5.2.1
    • v8.0.5
    • v7.2.8
    • v7.3.8
    • v6.3.0
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    • 5.4.54
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    Vendors and products

    Weakness classes (CWE)

    • CWE-1333Inefficient Regular Expression Complexity

      Base

      The product uses a regular expression with a worst-case computational complexity that is inefficient and possibly exponential.

      Entry at MITRE CWE-1333

    References & sources

    • github.comsymfony/symfony/pull/66048Patch, web
    • github.comsymfony/symfony/pull/66491Patch, web
    • github.comsymfony/symfony/security/advisories/GHSA-r925-mgvr-h9ccVendor advisory, web
    • symfony.comblog/cve-2026-108082-redos-in-headerutils-split-reachable-throu…Vendor advisory, web
    • NVD (NIST)vuln/detail/CVE-2026-108082advisory
    • github.comsymfony/symfony/commit/343a1772ce6ac03e48b228d2d7168d19750e3f36web
    • github.comsymfony/symfony/commit/9ffa802e5d7e9fb8ba95eeefd27e863e83b1bacaweb
    • github.comFriendsOfPHP/security-advisories/blob/master/symfony/http-found…web
    • github.comFriendsOfPHP/security-advisories/blob/master/symfony/symfony/CV…web
    • github.comsymfony/symfonypackage
    • github.comsymfony/symfony/releases/tag/v5.4.54web
    • github.comsymfony/symfony/releases/tag/v6.4.48web
    • github.comsymfony/symfony/releases/tag/v7.4.21web
    • github.comsymfony/symfony/releases/tag/v8.1.9web
    • symfony.comcve-2026-108082web

    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 modifiedCISA ADP

      CISA assessment (SSVC): exploitation: none known, automatable: yes

      Show the original change
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      SSVC assessmentadded
      —
      {"id":"CVE-2026-108082","role":"CISA Coordinator","options":[{"exploitation":"none"},{"automatable":"yes"},{"technicalImpact":"partial"}],"version":"2.0.3","timestamp":"2026-10-15T18:04:09.776300Z"}

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

    2. Record modified596c5446…

      Description added or changed

      Show the original change
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Descriptionchanged
      Symfony is a PHP framework for web and console applications and a set of reusable PHP components. Prior to versions 5.4.54, 6.4.46, 7.4.19, and 8.1.7, HeaderUtils::split() parsed header values with a pattern whose token alternative also matched whitespace, followed by a (?<!\s) lookbehind. A run of whitespace placed before a separator could be divided among the iterations of the enclosing repetition in exponentially many ways, and the engine tried all of them before settling. HeaderBag calls it for the Cache-Control header whenever a Request is built, so any application handling HTTP requests is reachable, with no authentication. A single request carrying such a header costs close to a second of CPU (813 ms for a run of 17 spaces in an 8 KB header on PHP 8.5, doubling with each extra space). From 18 spaces on, preg_match_all() gives up at pcre.backtrack_limit and split() returns an empty array, so every directive of the header is silently dropped. This issue affects symfony/http-foundation v4.1.0-BETA1 prior to v5.4.54, v6.0.0-BETA1 prior to v6.4.46, v7.0.0-BETA1 prior to v7.4.19, and v8.0.0-BETA1 prior to v8.1.7.
      Symfony is a PHP framework for web and console applications and a set of reusable PHP components. Prior to versions 5.4.54, 6.4.46, 7.4.19, and 8.1.7, HeaderUtils::split() parsed header values with a pattern whose token alternative also matched whitespace, followed by a (?<!\s) lookbehind. A run of whitespace placed before a separator could be divided among the iterations of the enclosing repetition in exponentially many ways, and the engine tried all of them before settling. HeaderBag calls it for the Cache-Control header whenever a Request is built, so any application handling HTTP requests is reachable, with no authentication. A single request carrying such a header costs close to a second of CPU (813 ms for a run of 17 spaces in an 8 KB header on PHP 8.5, doubling with each extra space). From 18 spaces on, preg_match_all() gives up at pcre.backtrack_limit and split() returns an empty array, so every directive of the header is silently dropped. This issue affects symfony/http-foundation v4.1.0-BETA1 through v5.4.53, v6.0.0-BETA1 through v6.4.45, v7.0.0-BETA1 through v7.4.18, and v8.0.0-BETA1 through v8.1.6.

      Source identifier: 596c5446-0ce5-4ba2-aa66-48b3b757a647

    3. Received596c5446…

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

      Weakness type: CWE-1333

      Description added or changed

      Show 8 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Descriptionadded
      —
      Symfony is a PHP framework for web and console applications and a set of reusable PHP components. Prior to versions 5.4.54, 6.4.46, 7.4.19, and 8.1.7, HeaderUtils::split() parsed header values with a pattern whose token alternative also matched whitespace, followed by a (?<!\s) lookbehind. A run of whitespace placed before a separator could be divided among the iterations of the enclosing repetition in exponentially many ways, and the engine tried all of them before settling. HeaderBag calls it for the Cache-Control header whenever a Request is built, so any application handling HTTP requests is reachable, with no authentication. A single request carrying such a header costs close to a second of CPU (813 ms for a run of 17 spaces in an 8 KB header on PHP 8.5, doubling with each extra space). From 18 spaces on, preg_match_all() gives up at pcre.backtrack_limit and split() returns an empty array, so every directive of the header is silently dropped. This issue affects symfony/http-foundation v4.1.0-BETA1 prior to v5.4.54, v6.0.0-BETA1 prior to v6.4.46, v7.0.0-BETA1 prior to v7.4.19, and v8.0.0-BETA1 prior to v8.1.7.
      CVSSadded
      —
      AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/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
      Weakness type (CWE)added
      —
      CWE-1333
      Affected versions (publisher)added
      —
      New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/108xxx/CVE-2026-108082.json">CVE-2026-108082</a>
      Referenceadded
      —
      https://github.com/symfony/symfony/pull/66048
      Referenceadded
      —
      https://github.com/symfony/symfony/pull/66491
      Referenceadded
      —
      https://github.com/symfony/symfony/security/advisories/GHSA-r925-mgvr-h9cc
      Referenceadded
      —
      https://symfony.com/blog/cve-2026-108082-redos-in-headerutils-split-reachable-through-the-cache-control-request-header

      Source identifier: 596c5446-0ce5-4ba2-aa66-48b3b757a647

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