HighCVE-2026-31532

    Linux Kernel: Use-After-Free (CVE-2026-31532)

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

    What is affected, what to do

    In the Linux kernel, the following vulnerability has been resolved: can: raw: fix ro->uniq use-after-free in raw_rcv() raw_release() unregisters raw CAN receive filters via can_rx_unregister(), but receiver deletion is deferred with call_rcu(). This leaves a window where raw_rcv() may still be running in an RCU read-side critical section after raw_release() frees ro->uniq, leading to a use-after-free of the percpu uniq storage.

    Update Linux Kernel to version 5.10.258, Linux Kernel to version 5.15.209, Linux Kernel to version 6.1.175.

    Affected
    • Linux Kernel lt 4.1..5.10.258
    • Linux Kernel lt 5.11..5.15.209
    • Linux Kernel lt 5.16..6.1.175
    • Linux Kernel lt 6.2..6.6.136
    • Linux Kernel lt 6.7..6.12.83
    • Linux Kernel lt 6.13..6.18.24
    • Linux Kernel lt 6.19..6.19.14
    • Linux Kernel lt 6.20..7.0.1
    Fixed in
    • Linux Kernel 5.10.258
    • Linux Kernel 5.15.209
    • Linux Kernel 6.1.175
    • Linux Kernel 6.6.136
    • Linux Kernel 6.12.83
    • Linux Kernel 6.18.24
    • Linux Kernel 6.19.14
    • Linux Kernel 7.0.1
    • Linux Kernel 7.1

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

    Metrics

    7.8

    Priority

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

    Source: NVD, CVSS v3

    7.8

    CVSS v3

    Severity High on the scale from 0 to 10.

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

    0.2 %

    EPSS score

    Low — model estimates < 1% exploitation likelihood.

    Source: FIRST EPSS, percentile 5.7

    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
    55.82 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
    7.8 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
    7.8
    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
    0.2 %
    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
    5.7
    Low — this CVE sits in the lower 10% of all CVEs scored today.
    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 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-416

    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

    In the Linux kernel, the following vulnerability has been resolved: can: raw: fix ro->uniq use-after-free in raw_rcv() raw_release() unregisters raw CAN receive filters via can_rx_unregister(), but receiver deletion is deferred with call_rcu(). This leaves a window where raw_rcv() may still be running in an RCU read-side critical section after raw_release() frees ro->uniq, leading to a use-after-free of the percpu uniq storage. Move free_percpu(ro->uniq) out of raw_release() and into a raw-specific socket destructor. can_rx_unregister() takes an extra reference to the socket and only drops it from the RCU callback, so freeing uniq from sk_destruct ensures the percpu area is not released until the relevant callbacks have drained. [mkl: applied manually]

    Source: suse_csaf, Debian Security Advisories, Ubuntu Security Notices, Debian LTS Advisories, siemens_advisory, redhat_csaf, BSI WID Portal, BSI CSAF, cvelistv5, NVD (NIST), ENISA EUVD, CVE.org (MITRE), Microsoft Security Update Guide

    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
    • 5.16 – < 6.1.175
    • 6.2 – < 6.6.136
    • 4.1 – < 5.10.258
    • 6.19 – < 6.19.14
    • 5.11 – < 5.15.209
    • 6.13 – < 6.18.24
    • —
    • 6.7 – < 6.12.83
    • 6.20 – < 7.0.1
    • 6.1.175
    • 6.6.136
    • 5.10.258
    • 6.19.14
    • 5.15.209
    • 6.18.24
    • 7.1
    • 6.12.83
    • 7.0.1
    IBMDataPower Gateway
    • < 11.0.0.3
    • < 10.6.0.11
    • < 10.5.0.23
    • 11.0.0.3
    • 10.6.0.11
    • 10.5.0.23
    SiemensSIMATIC S7
    • 1500 TM MFP V1.1.1 GNU/Linux subsystem
    • —

    Vendors and products

    Affected operating systems

    Affected operating systems
    Linuxdebianlinuxbookworm
    Linuxdebianlinuxbullseye
    Linuxdebianlinuxtrixie
    Linuxdebianlinux-6.1bullseye
    Linuxlinuxlinux_kernel—

    Weakness classes (CWE)

    • CWE-416Use After Free

      Variant

      The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.

      Entry at MITRE CWE-416

    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-416

      Show the original change
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Weakness type (CWE)added
      —
      CWE-416

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

    2. 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-2026-31532","role":"CISA Coordinator","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T15:10:40.984593Z"}

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

    3. Record modifiedLinux

      Show 24 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Referenceadded
      —
      https://git.kernel.org/stable/c/1a0f2de81f7fbdc538fc72d7d74609b79bc83cc0
      Referenceadded
      —
      https://git.kernel.org/stable/c/1de30576a6dfeaaa27ef91fa272e6b9240b6fbd3
      Referenceadded
      —
      https://git.kernel.org/stable/c/34c1741254ff972e8375faf176678a248826fe3a
      Referenceadded
      —
      https://git.kernel.org/stable/c/3f43f12fde34737fba091b7e3ab391e14ddbb0be
      Referenceadded
      —
      https://git.kernel.org/stable/c/572f0bf536ebc14f6e7da3d21a85cf076de8358e
      Referenceadded
      —
      https://git.kernel.org/stable/c/5e9cfffad898bbeaafd0ea608a6d267362f050fc
      Referenceadded
      —
      https://git.kernel.org/stable/c/64c8553decf5a5f2417bd54761ea0a832c56c4ca
      Referenceadded
      —
      https://git.kernel.org/stable/c/7201a531b9a5ed892bfda5ded9194ef622de8ffa
      Referenceadded
      —
      https://git.kernel.org/stable/c/a535a9217ca3f2fccedaafb2fddb4c48f27d36dc
      Referenceremoved
      https://git.kernel.org/stable/c/1a0f2de81f7fbdc538fc72d7d74609b79bc83cc0
      —
      Referenceremoved
      https://git.kernel.org/stable/c/1de30576a6dfeaaa27ef91fa272e6b9240b6fbd3
      —
      Referenceremoved
      https://git.kernel.org/stable/c/34c1741254ff972e8375faf176678a248826fe3a
      —
      Referenceremoved
      https://git.kernel.org/stable/c/3f43f12fde34737fba091b7e3ab391e14ddbb0be
      —
      Referenceremoved
      https://git.kernel.org/stable/c/572f0bf536ebc14f6e7da3d21a85cf076de8358e
      —
      Referenceremoved
      https://git.kernel.org/stable/c/5e9cfffad898bbeaafd0ea608a6d267362f050fc
      —
      Referenceremoved
      https://git.kernel.org/stable/c/64c8553decf5a5f2417bd54761ea0a832c56c4ca
      —
      Referenceremoved
      https://git.kernel.org/stable/c/7201a531b9a5ed892bfda5ded9194ef622de8ffa
      —
      Referenceremoved
      https://git.kernel.org/stable/c/a535a9217ca3f2fccedaafb2fddb4c48f27d36dc
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/1a0f2de81f7fbdc538fc72d7d74609b79bc83cc0 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/34c1741254ff972e8375faf176678a248826fe3a Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/572f0bf536ebc14f6e7da3d21a85cf076de8358e Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/5e9cfffad898bbeaafd0ea608a6d267362f050fc Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/7201a531b9a5ed892bfda5ded9194ef622de8ffa Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/a535a9217ca3f2fccedaafb2fddb4c48f27d36dc 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/2026/31xxx/CVE-2026-31532.json">CVE-2026-31532</a>
      Referenceadded
      —
      https://cert-portal.siemens.com/productcert/html/ssa-784472.html

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

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