CriticalCVE-2026-46185

    Linux Kernel: Out-of-Bounds Read (CVE-2026-46185)

    Published Last modified Sources: Ubuntu, Debian LTS, SUSE, Siemens ProductCERT, Red Hat, Msrc Update Guide, CVE.org, EUVD, BSI

    What is affected, what to do

    A flaw was found in the Linux kernel's Server Message Block (SMB) client. This vulnerability arises from insufficient length validation in the `smb2_check_message()` function when processing symlink error responses.

    The available sources name no fixed version. Check the vendor guidance in the references below.

    Conflicting version data — version display is hidden until the data is resolved.

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

    Metrics

    9.1

    Priority

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

    Source: Vendor (CNA), CVSS v3

    9.1

    CVSS v3

    Severity Critical on the scale from 0 to 10.

    Source: Ubuntu, Debian LTS, SUSE, Siemens ProductCERT, Red Hat, Msrc Update Guide, CVE.org, EUVD, BSI

    0.5 %

    EPSS score

    Low — model estimates < 1% exploitation likelihood.

    Source: FIRST EPSS, percentile 44.5

    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
    79.23 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
    9.1 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
    9.1
    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
    44.5
    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 16 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-125

    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 the Linux kernel's Server Message Block (SMB) client. This vulnerability arises from insufficient length validation in the `smb2_check_message()` function when processing symlink error responses. A remote attacker could exploit this by sending a specially crafted symlink error response, which may lead to an out-of-bounds read in the `symlink_data()` function. This could potentially result in information disclosure or a denial of service.

    Source: Ubuntu Security Notices, Debian LTS Advisories, suse_csaf, siemens_advisory, redhat_csaf, Microsoft Security Update Guide, cvelistv5, NVD (NIST), ENISA EUVD, CVE.org (MITRE), 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
    LinuxLinux
    • 6.7 – < 6.12.88
    • 6.2 – < 6.6.140
    • 6.19 – < 7.0.7
    • —
    • 6.0.16 – < 6.1
    • 6.1 – < 6.1.175
    • 6.13 – < 6.18.30
    • 6.12.88
    • 6.6.140
    • 7.0.7
    • 7.1
    • 6.1
    • 6.1.175
    • 6.18.30
    SiemensSIMATIC S7
    • 1500 TM MFP V1.1.1 GNU/Linux subsystem
    • —

    Vendors and products

    Affected operating systems

    Affected operating systems
    Linuxdebianlinuxbookworm
    Linuxdebianlinux-6.1bullseye
    Linuxlinuxlinux_kernel7.1
    Linuxlinuxlinux_kernel—

    Weakness classes (CWE)

    • CWE-125Out-of-bounds Read

      Base

      The product reads data past the end, or before the beginning, of the intended buffer.

      Entry at MITRE CWE-125

    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 modifiedCISA ADP

      Weakness type: CWE-125

      Show the original change
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Weakness type (CWE)added
      —
      CWE-125

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

    2. 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-2026-46185","role":"CISA Coordinator","options":[{"exploitation":"none"},{"automatable":"yes"},{"technicalImpact":"partial"}],"version":"2.0.3","timestamp":"2026-10-16T15:20:54.231422Z"}

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

    3. Record modifiedLinux

      Show 18 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Referenceadded
      —
      https://git.kernel.org/stable/c/15dc0a4de743a1aaa7b859b3aea79f08c695396c
      Referenceadded
      —
      https://git.kernel.org/stable/c/2be11faf79e49fb8250a181ff0b4d2b2f084af83
      Referenceadded
      —
      https://git.kernel.org/stable/c/b8c8a704f0bc133deb171f6aeb6f3a684203e212
      Referenceadded
      —
      https://git.kernel.org/stable/c/b9561402489d41149f63e001a74384863b7b30a6
      Referenceadded
      —
      https://git.kernel.org/stable/c/d62b8d236fab503c6fec1d3e9a38bea71feaca20
      Referenceadded
      —
      https://git.kernel.org/stable/c/ef6495d4df6e7af8f3de67e65150881c880f696c
      Referenceremoved
      https://git.kernel.org/stable/c/15dc0a4de743a1aaa7b859b3aea79f08c695396c
      —
      Referenceremoved
      https://git.kernel.org/stable/c/2be11faf79e49fb8250a181ff0b4d2b2f084af83
      —
      Referenceremoved
      https://git.kernel.org/stable/c/b8c8a704f0bc133deb171f6aeb6f3a684203e212
      —
      Referenceremoved
      https://git.kernel.org/stable/c/b9561402489d41149f63e001a74384863b7b30a6
      —
      Referenceremoved
      https://git.kernel.org/stable/c/d62b8d236fab503c6fec1d3e9a38bea71feaca20
      —
      Referenceremoved
      https://git.kernel.org/stable/c/ef6495d4df6e7af8f3de67e65150881c880f696c
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/15dc0a4de743a1aaa7b859b3aea79f08c695396c Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/2be11faf79e49fb8250a181ff0b4d2b2f084af83 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/b8c8a704f0bc133deb171f6aeb6f3a684203e212 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/b9561402489d41149f63e001a74384863b7b30a6 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/d62b8d236fab503c6fec1d3e9a38bea71feaca20 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/ef6495d4df6e7af8f3de67e65150881c880f696c Types: Patch
      —

      Source identifier: 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    4. Record modifiedSiemens ADP

      Show 2 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Affected versions (publisher)added
      —
      New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/46xxx/CVE-2026-46185.json">CVE-2026-46185</a>
      Referenceadded
      —
      https://cert-portal.siemens.com/productcert/html/ssa-784472.html

      Source identifier: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e

    5. Initial analysis by NVDNVD

      Newly listed as affected:
      • Linux Kernel (6.13 – before 6.18.30; 6.19 – before 7.0.7; 6.7 – before 6.12.88; 6.2 – before 6.6.140; 6.0.16 – before 6.1.175; 2 individual versions)

      Weakness type: CWE-125

      Show 8 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Weakness type (CWE)added
      —
      CWE-125
      Product configurationadded
      —
      OR *cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.13 up to (excluding) 6.18.30 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.19 up to (excluding) 7.0.7 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.7 up to (excluding) 6.12.88 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.2 up to (excluding) 6.6.140 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.0.16 up to (excluding) 6.1.175
      Reference typeadded
      —
      kernel.org: https://git.kernel.org/stable/c/15dc0a4de743a1aaa7b859b3aea79f08c695396c Types: Patch
      Reference typeadded
      —
      kernel.org: https://git.kernel.org/stable/c/2be11faf79e49fb8250a181ff0b4d2b2f084af83 Types: Patch
      Reference typeadded
      —
      kernel.org: https://git.kernel.org/stable/c/b8c8a704f0bc133deb171f6aeb6f3a684203e212 Types: Patch
      Reference typeadded
      —
      kernel.org: https://git.kernel.org/stable/c/b9561402489d41149f63e001a74384863b7b30a6 Types: Patch
      Reference typeadded
      —
      kernel.org: https://git.kernel.org/stable/c/d62b8d236fab503c6fec1d3e9a38bea71feaca20 Types: Patch
      Reference typeadded
      —
      kernel.org: https://git.kernel.org/stable/c/ef6495d4df6e7af8f3de67e65150881c880f696c Types: Patch

      Source identifier: nvd@nist.gov

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