HighCVE-2026-31580

    Linux Kernel: Use-After-Free (CVE-2026-31580)

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

    What is affected, what to do

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

    0.1 %

    EPSS score

    Low — model estimates < 1% exploitation likelihood.

    Source: FIRST EPSS, percentile 2.7

    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
    55.67 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
    0.1 %
    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
    2.7
    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

    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:

    bcache: fix cached_dev.sb_bio use-after-free and crash

    In our production environment, we have received multiple crash reports regarding libceph, which have caught our attention:

    [6888366.280350] Call Trace:
[6888366.280452]  blk_update_request+0x14e/0x370
[6888366.280561]  blk_mq_end_request+0x1a/0x130
[6888366.280671]  rbd_img_handle_request+0x1a0/0x1b0 [rbd]
[6888366.280792]  rbd_obj_handle_request+0x32/0x40 [rbd]
[6888366.280903]  __complete_request+0x22/0x70 [libceph]
[6888366.281032]  osd_dispatch+0x15e/0xb40 [libceph]
[6888366.281164]  ? inet_recvmsg+0x5b/0xd0
[6888366.281272]  ? ceph_tcp_recvmsg+0x6f/0xa0 [libceph]
[6888366.281405]  ceph_con_process_message+0x79/0x140 [libceph]
[6888366.281534]  ceph_con_v1_try_read+0x5d7/0xf30 [libceph]
[6888366.281661]  ceph_con_workfn+0x329/0x680 [libceph]

    After analyzing the coredump file, we found that the address of dc->sb_bio has been freed. We know that cached_dev is only freed when it is stopped.

    Since sb_bio is a part of struct cached_dev, rather than an alloc every time. If the device is stopped while writing to the superblock, the released address will be accessed at endio.

    This patch hopes to wait for sb_write to complete in cached_dev_free.

    It should be noted that we analyzed the cause of the problem, then tell all details to the QWEN and adopted the modifications it made.

    Source: Debian Security Advisories, Debian LTS Advisories, suse_csaf, Ubuntu Security Notices, siemens_advisory, BSI WID Portal, BSI CSAF, NVD (NIST), CVE.org (MITRE), Microsoft Security Update Guide, cvelistv5, 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
    • 6.2 – < 6.6.136
    • 6.19 – < 6.19.14
    • 5.11 – < 5.15.209
    • 6.13 – < 6.18.24
    • 3.10 – < 5.10.258
    • —
    • 6.7 – < 6.12.83
    • 6.20 – < 7.0.1
    • 6.1.175
    • 6.6.136
    • 6.19.14
    • 5.15.209
    • 6.18.24
    • 5.10.258
    • 7.1
    • 6.12.83
    • 7.0.1
    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—

    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 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-2026-31580.json">CVE-2026-31580</a>
      Referenceadded
      —
      https://cert-portal.siemens.com/productcert/html/ssa-784472.html

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

    2. Record modifiedLinux

      Show 24 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Referenceadded
      —
      https://git.kernel.org/stable/c/2d6965581e164fa2ba3f7652ddae5535f6336576
      Referenceadded
      —
      https://git.kernel.org/stable/c/383f7fec0de8cee1cf7ae1f9d9f14044a61f10f9
      Referenceadded
      —
      https://git.kernel.org/stable/c/47fa09fe7f3e09df28a51cb2cbd8f5d2f7f6edc1
      Referenceadded
      —
      https://git.kernel.org/stable/c/4f71c8ba2dc009042493021d94a9718fbe2ebf27
      Referenceadded
      —
      https://git.kernel.org/stable/c/81f44ed8c3f54abb7561ece774ea4cca5070b2f2
      Referenceadded
      —
      https://git.kernel.org/stable/c/9467d360be70e6ee55b0c1cd2a1f1424f57b5b85
      Referenceadded
      —
      https://git.kernel.org/stable/c/add4982510f3b7c318a2dd7438bdc9c63171e753
      Referenceadded
      —
      https://git.kernel.org/stable/c/f50e7c325ab1207fe941555bcff659f6d7050572
      Referenceadded
      —
      https://git.kernel.org/stable/c/fec114a98b8735ee89c75216c45a78e28be0f128
      Referenceremoved
      https://git.kernel.org/stable/c/2d6965581e164fa2ba3f7652ddae5535f6336576
      —
      Referenceremoved
      https://git.kernel.org/stable/c/383f7fec0de8cee1cf7ae1f9d9f14044a61f10f9
      —
      Referenceremoved
      https://git.kernel.org/stable/c/47fa09fe7f3e09df28a51cb2cbd8f5d2f7f6edc1
      —
      Referenceremoved
      https://git.kernel.org/stable/c/4f71c8ba2dc009042493021d94a9718fbe2ebf27
      —
      Referenceremoved
      https://git.kernel.org/stable/c/81f44ed8c3f54abb7561ece774ea4cca5070b2f2
      —
      Referenceremoved
      https://git.kernel.org/stable/c/9467d360be70e6ee55b0c1cd2a1f1424f57b5b85
      —
      Referenceremoved
      https://git.kernel.org/stable/c/add4982510f3b7c318a2dd7438bdc9c63171e753
      —
      Referenceremoved
      https://git.kernel.org/stable/c/f50e7c325ab1207fe941555bcff659f6d7050572
      —
      Referenceremoved
      https://git.kernel.org/stable/c/fec114a98b8735ee89c75216c45a78e28be0f128
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/2d6965581e164fa2ba3f7652ddae5535f6336576 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/383f7fec0de8cee1cf7ae1f9d9f14044a61f10f9 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/47fa09fe7f3e09df28a51cb2cbd8f5d2f7f6edc1 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/4f71c8ba2dc009042493021d94a9718fbe2ebf27 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/add4982510f3b7c318a2dd7438bdc9c63171e753 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/fec114a98b8735ee89c75216c45a78e28be0f128 Types: Patch
      —

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

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