MediumCVE-2026-45838

    Linux Kernel: security vulnerability (CVE-2026-45838)

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

    What is affected, what to do

    In the Linux kernel, the following vulnerability has been resolved: bpf: fix end-of-list detection in cgroup_storage_get_next_key() list_next_entry() never returns NULL -- when the current element is the last entry it wraps to the list head via container_of(). The subsequent NULL check is therefore dead code and get_next_key() never returns -ENOENT for the last element, instead reading storage->key from a bogus pointer that aliases internal map fields and copying the result to userspace.

    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 4.19..5.10.258
    • Linux Kernel lt 5.11..5.15.209
    • Linux Kernel lt 5.16..6.1.175
    • Linux Kernel lt 6.2..6.6.141
    • Linux Kernel lt 6.7..6.12.91
    • Linux Kernel lt 6.13..6.18.33
    • Linux Kernel lt 6.19..7.0.10
    Fixed in
    • Linux Kernel 5.10.258
    • Linux Kernel 5.15.209
    • Linux Kernel 6.1.175
    • Linux Kernel 6.6.141
    • Linux Kernel 6.12.91
    • Linux Kernel 6.18.33
    • Linux Kernel 7.0.10
    • Linux Kernel 7.1

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

    0.1 %

    EPSS score

    Low — model estimates < 1% exploitation likelihood.

    Source: FIRST EPSS, percentile 2.6

    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
    45.56 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
    2.6
    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: bpf: fix end-of-list detection in cgroup_storage_get_next_key() list_next_entry() never returns NULL -- when the current element is the last entry it wraps to the list head via container_of(). The subsequent NULL check is therefore dead code and get_next_key() never returns -ENOENT for the last element, instead reading storage->key from a bogus pointer that aliases internal map fields and copying the result to userspace. Replace it with list_entry_is_head() so the function correctly returns -ENOENT when there are no more entries.

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

    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
    • 4.19 – < 5.10.258
    • 5.11 – < 5.15.209
    • 6.7 – < 6.12.91
    • —
    • 6.13 – < 6.18.33
    • 6.2 – < 6.6.141
    • 6.19 – < 7.0.10
    • 6.1.175
    • 5.10.258
    • 5.15.209
    • 6.12.91
    • 7.1
    • 6.18.33
    • 6.6.141
    • 7.0.10
    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
    Linuxubuntulinux-oracle-7.0noble
    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 24 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Referenceadded
      —
      https://git.kernel.org/stable/c/0f3d9dd5e1fd52b39e25328307c6a694e994ffe3
      Referenceadded
      —
      https://git.kernel.org/stable/c/26d3339e465e54107bd85884341d1609c5300d6a
      Referenceadded
      —
      https://git.kernel.org/stable/c/2c88b2d96e1d4d0c7c4589a4593d4cdee6d332d6
      Referenceadded
      —
      https://git.kernel.org/stable/c/32ce55d424395904986f5066f8755f6cb9993377
      Referenceadded
      —
      https://git.kernel.org/stable/c/5828b9e5b272ecff7cf5d345128d3de7324117f7
      Referenceadded
      —
      https://git.kernel.org/stable/c/85a2f30e40f7468db732f55659bc6318874f49af
      Referenceadded
      —
      https://git.kernel.org/stable/c/b4b5a20bed82130da2f2818f04d52378952fbd0b
      Referenceadded
      —
      https://git.kernel.org/stable/c/fc39753b7f92e09177777e9c648afe5aa3abb81f
      Referenceremoved
      https://git.kernel.org/stable/c/0f3d9dd5e1fd52b39e25328307c6a694e994ffe3
      —
      Referenceremoved
      https://git.kernel.org/stable/c/26d3339e465e54107bd85884341d1609c5300d6a
      —
      Referenceremoved
      https://git.kernel.org/stable/c/2c88b2d96e1d4d0c7c4589a4593d4cdee6d332d6
      —
      Referenceremoved
      https://git.kernel.org/stable/c/32ce55d424395904986f5066f8755f6cb9993377
      —
      Referenceremoved
      https://git.kernel.org/stable/c/5828b9e5b272ecff7cf5d345128d3de7324117f7
      —
      Referenceremoved
      https://git.kernel.org/stable/c/85a2f30e40f7468db732f55659bc6318874f49af
      —
      Referenceremoved
      https://git.kernel.org/stable/c/b4b5a20bed82130da2f2818f04d52378952fbd0b
      —
      Referenceremoved
      https://git.kernel.org/stable/c/fc39753b7f92e09177777e9c648afe5aa3abb81f
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/0f3d9dd5e1fd52b39e25328307c6a694e994ffe3 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/26d3339e465e54107bd85884341d1609c5300d6a Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/2c88b2d96e1d4d0c7c4589a4593d4cdee6d332d6 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/32ce55d424395904986f5066f8755f6cb9993377 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/5828b9e5b272ecff7cf5d345128d3de7324117f7 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/85a2f30e40f7468db732f55659bc6318874f49af Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/b4b5a20bed82130da2f2818f04d52378952fbd0b Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/fc39753b7f92e09177777e9c648afe5aa3abb81f 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/2026/45xxx/CVE-2026-45838.json">CVE-2026-45838</a>
      Referenceadded
      —
      https://cert-portal.siemens.com/productcert/html/ssa-784472.html

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

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