MediumCVE-2026-31642

    Linux Kernel: Infinite Loop (CVE-2026-31642)

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

    What is affected, what to do

    In the Linux kernel, the following vulnerability has been resolved: rxrpc: Fix call removal to use RCU safe deletion Fix rxrpc call removal from the rxnet->calls list to use list_del_rcu() rather than list_del_init() to prevent stuffing up reading /proc/net/rxrpc/calls from potentially getting into an infinite loop. This, however, means that list_empty() no longer works on an entry that's been deleted from the list, making it harder to detect prior deletion.

    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 4.13..5.10.258
    • Linux Kernel lt 5.11..5.15.209
    • Linux Kernel lt 5.16..6.1.175
    • Linux Kernel lt 6.2..6.6.135
    • Linux Kernel lt 6.7..6.12.82
    • Linux Kernel lt 6.13..6.18.23
    • Linux Kernel lt 6.19..6.19.13
    • Linux Kernel lt 6.20..7.0
    Fixed in
    • Linux Kernel 5.10.258
    • Linux Kernel 5.15.209
    • Linux Kernel 6.1.175
    • Linux Kernel 6.6.135
    • Linux Kernel 6.12.82
    • Linux Kernel 6.18.23
    • Linux Kernel 6.19.13
    • Linux Kernel 7.0

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

    Metrics

    5.5

    Priority

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

    Source: NVD, CVSS v3

    5.5

    CVSS v3

    Severity Medium on the scale from 0 to 10.

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

    0.1 %

    EPSS score

    Low — model estimates < 1% exploitation likelihood.

    Source: FIRST EPSS, percentile 2.5

    Show all metrics
    Severity
    Medium
    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
    44.12 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
    5.5 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
    5.5
    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
    0.1 %
    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
    2.5
    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

    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
    Handle the vulnerability in regular vulnerability handling under Art. 21(2)(e) NIS2.
    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: rxrpc: Fix call removal to use RCU safe deletion Fix rxrpc call removal from the rxnet->calls list to use list_del_rcu() rather than list_del_init() to prevent stuffing up reading /proc/net/rxrpc/calls from potentially getting into an infinite loop. This, however, means that list_empty() no longer works on an entry that's been deleted from the list, making it harder to detect prior deletion. Fix this by: Firstly, make rxrpc_destroy_all_calls() only dump the first ten calls that are unexpectedly still on the list. Limiting the number of steps means there's no need to call cond_resched() or to remove calls from the list here, thereby eliminating the need for rxrpc_put_call() to check for that. rxrpc_put_call() can then be fixed to unconditionally delete the call from the list as it is the only place that the deletion occurs.

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

    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
    • 6.7 – < 6.12.82
    • 6.2 – < 6.6.135
    • 5.11 – < 5.15.209
    • 6.13 – < 6.18.23
    • 6.19 – < 6.19.13
    • 6.20 – < 7.0
    • 4.13 – < 5.10.258
    • 6.1.175
    • 6.12.82
    • 6.6.135
    • 5.15.209
    • 6.18.23
    • 6.19.13
    • 7.0
    • 5.10.258
    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_kernel4.13
    Linuxlinuxlinux_kernel7.0
    Linuxlinuxlinux_kernel—

    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 modifiedLinux

      Show 21 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Referenceadded
      —
      https://git.kernel.org/stable/c/146d4ab94cf129ee06cd467cb5c71368a6b5bad6
      Referenceadded
      —
      https://git.kernel.org/stable/c/280efb85e9759881a9d31d0874baa04583cb6c09
      Referenceadded
      —
      https://git.kernel.org/stable/c/3be718f659683ad89fad6f1eb66bee99727cae64
      Referenceadded
      —
      https://git.kernel.org/stable/c/3e47a38e584b905359fe0ce5be5165d1e8592a90
      Referenceadded
      —
      https://git.kernel.org/stable/c/93fc15be44a35b8e3c58d0238ac0d9b7c53465ff
      Referenceadded
      —
      https://git.kernel.org/stable/c/ac5f54691be06a32246179d41be2d73598036deb
      Referenceadded
      —
      https://git.kernel.org/stable/c/b15b1ce96777b88989a6a4de8d01efbcd81ad2d7
      Referenceadded
      —
      https://git.kernel.org/stable/c/c63abf25203b50243fe228090526f9dbf37727bd
      Referenceremoved
      https://git.kernel.org/stable/c/146d4ab94cf129ee06cd467cb5c71368a6b5bad6
      —
      Referenceremoved
      https://git.kernel.org/stable/c/280efb85e9759881a9d31d0874baa04583cb6c09
      —
      Referenceremoved
      https://git.kernel.org/stable/c/3be718f659683ad89fad6f1eb66bee99727cae64
      —
      Referenceremoved
      https://git.kernel.org/stable/c/3e47a38e584b905359fe0ce5be5165d1e8592a90
      —
      Referenceremoved
      https://git.kernel.org/stable/c/93fc15be44a35b8e3c58d0238ac0d9b7c53465ff
      —
      Referenceremoved
      https://git.kernel.org/stable/c/ac5f54691be06a32246179d41be2d73598036deb
      —
      Referenceremoved
      https://git.kernel.org/stable/c/b15b1ce96777b88989a6a4de8d01efbcd81ad2d7
      —
      Referenceremoved
      https://git.kernel.org/stable/c/c63abf25203b50243fe228090526f9dbf37727bd
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/146d4ab94cf129ee06cd467cb5c71368a6b5bad6 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/3be718f659683ad89fad6f1eb66bee99727cae64 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/93fc15be44a35b8e3c58d0238ac0d9b7c53465ff Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/ac5f54691be06a32246179d41be2d73598036deb Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/c63abf25203b50243fe228090526f9dbf37727bd Types: Patch
      —

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

    2. 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-2026-31642.json">CVE-2026-31642</a>
      Referenceadded
      —
      https://cert-portal.siemens.com/productcert/html/ssa-784472.html

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

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