MediumCVE-2026-52930

    Linux Kernel: security vulnerability (CVE-2026-52930)

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

    ShareLinkedInXINGXBlueskyEmail

    What is affected, what to do

    In the Linux kernel, the following vulnerability has been resolved: ipc/shm: serialize orphan cleanup with shm_nattch updates shm_destroy_orphaned() walks the shm idr under shm_ids(ns).rwsem, but that does not serialize all fields tested by shm_may_destroy(). In particular, shm_nattch is updated while holding shm_perm.lock, and attach paths can do that without holding the rwsem.

    Update Linux Kernel to version 5.10.259, Linux Kernel to version 5.15.210, Linux Kernel to version 6.1.176.

    Affected
    • Linux Kernel lt 3.1..5.10.259
    • Linux Kernel lt 5.11..5.15.210
    • Linux Kernel lt 5.16..6.1.176
    • Linux Kernel lt 6.2..6.6.143
    • Linux Kernel lt 6.7..6.12.94
    • Linux Kernel lt 6.13..6.18.36
    • Linux Kernel lt 6.19..7.0.13
    Fixed in
    • Linux Kernel 5.10.259
    • Linux Kernel 5.15.210
    • Linux Kernel 6.1.176
    • Linux Kernel 6.6.143
    • Linux Kernel 6.12.94
    • Linux Kernel 6.18.36
    • Linux Kernel 7.0.13
    • 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: SUSE, Siemens ProductCERT, Debian LTS, Ubuntu, BSI, Msrc Update Guide, CVE.org

    0.1 %

    EPSS score

    Low — model estimates < 1% exploitation likelihood.

    Source: FIRST EPSS, percentile 1.8

    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
    46.81 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
    1.8
    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: ipc/shm: serialize orphan cleanup with shm_nattch updates shm_destroy_orphaned() walks the shm idr under shm_ids(ns).rwsem, but that does not serialize all fields tested by shm_may_destroy(). In particular, shm_nattch is updated while holding shm_perm.lock, and attach paths can do that without holding the rwsem. Do not decide that an orphaned segment is unused before taking the object lock. Move the shm_may_destroy() check under shm_perm.lock, matching the other destroy paths, and unlock the segment when it no longer qualifies for removal.

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

    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 – < 6.12.94
    • 6.13 – < 6.18.36
    • 5.11 – < 5.15.210
    • 3.1 – < 5.10.259
    • —
    • 5.16 – < 6.1.176
    • 6.19 – < 7.0.13
    • 6.2 – < 6.6.143
    • 6.12.94
    • 6.18.36
    • 5.15.210
    • 5.10.259
    • 7.1
    • 6.1.176
    • 7.0.13
    • 6.6.143
    SiemensSIMATIC S7
    • 1500 TM MFP V1.1.1 GNU/Linux subsystem
    • —

    Vendors and products

    Affected operating systems

    Affected operating systems
    Linuxdebianlinuxbookworm
    Linuxdebianlinuxbullseye
    Linuxdebianlinux-6.1bullseye
    Linuxubuntulinux-oracle-7.0noble
    Linuxlinuxlinux_kernel7.1
    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 3 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Affected versions (publisher)added
      —
      Affected value modified. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/52xxx/CVE-2026-52930.json">CVE-2026-52930</a>
      Referenceadded
      —
      https://cert-portal.siemens.com/productcert/html/ssa-457936.html
      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/030bbc857bd51d4b25a90d931d3f8775ef22823a
      Referenceadded
      —
      https://git.kernel.org/stable/c/1f0d01e35dbb228084d5187212e32c91a30dcbeb
      Referenceadded
      —
      https://git.kernel.org/stable/c/2e5c6f4fd4001562781e99bbfc7f1f0127187542
      Referenceadded
      —
      https://git.kernel.org/stable/c/6560be3f6a5bb84f006f184f0c966747bb58e1a3
      Referenceadded
      —
      https://git.kernel.org/stable/c/92cda2593cf2ed25b0e9d78e5e6d8303bba1a064
      Referenceadded
      —
      https://git.kernel.org/stable/c/b1e9aef48e4d8a0c1b54fb913077b0824ed7d650
      Referenceadded
      —
      https://git.kernel.org/stable/c/b5107b4ce3ad45fcf369ee2058c8910620f4b5a8
      Referenceadded
      —
      https://git.kernel.org/stable/c/db752ebfdaf2c7f27cd9690ef48b616af068319c
      Referenceremoved
      https://git.kernel.org/stable/c/030bbc857bd51d4b25a90d931d3f8775ef22823a
      —
      Referenceremoved
      https://git.kernel.org/stable/c/1f0d01e35dbb228084d5187212e32c91a30dcbeb
      —
      Referenceremoved
      https://git.kernel.org/stable/c/2e5c6f4fd4001562781e99bbfc7f1f0127187542
      —
      Referenceremoved
      https://git.kernel.org/stable/c/6560be3f6a5bb84f006f184f0c966747bb58e1a3
      —
      Referenceremoved
      https://git.kernel.org/stable/c/92cda2593cf2ed25b0e9d78e5e6d8303bba1a064
      —
      Referenceremoved
      https://git.kernel.org/stable/c/b1e9aef48e4d8a0c1b54fb913077b0824ed7d650
      —
      Referenceremoved
      https://git.kernel.org/stable/c/b5107b4ce3ad45fcf369ee2058c8910620f4b5a8
      —
      Referenceremoved
      https://git.kernel.org/stable/c/db752ebfdaf2c7f27cd9690ef48b616af068319c
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/030bbc857bd51d4b25a90d931d3f8775ef22823a Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/1f0d01e35dbb228084d5187212e32c91a30dcbeb Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/2e5c6f4fd4001562781e99bbfc7f1f0127187542 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/6560be3f6a5bb84f006f184f0c966747bb58e1a3 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/92cda2593cf2ed25b0e9d78e5e6d8303bba1a064 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/b1e9aef48e4d8a0c1b54fb913077b0824ed7d650 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/b5107b4ce3ad45fcf369ee2058c8910620f4b5a8 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/db752ebfdaf2c7f27cd9690ef48b616af068319c Types: Patch
      —

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

    3. 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/2026/52xxx/CVE-2026-52930.json">CVE-2026-52930</a>
      Referenceadded
      —
      https://cert-portal.siemens.com/productcert/html/ssa-019113.html

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

    4. ReceivedLinux

      Description added or changed

      Show 10 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Affected versions (publisher)added
      —
      Linux, Linux
      Descriptionadded
      —
      In the Linux kernel, the following vulnerability has been resolved: ipc/shm: serialize orphan cleanup with shm_nattch updates shm_destroy_orphaned() walks the shm idr under shm_ids(ns).rwsem, but that does not serialize all fields tested by shm_may_destroy(). In particular, shm_nattch is updated while holding shm_perm.lock, and attach paths can do that without holding the rwsem. Do not decide that an orphaned segment is unused before taking the object lock. Move the shm_may_destroy() check under shm_perm.lock, matching the other destroy paths, and unlock the segment when it no longer qualifies for removal.
      Referenceadded
      —
      https://git.kernel.org/stable/c/030bbc857bd51d4b25a90d931d3f8775ef22823a
      Referenceadded
      —
      https://git.kernel.org/stable/c/1f0d01e35dbb228084d5187212e32c91a30dcbeb
      Referenceadded
      —
      https://git.kernel.org/stable/c/2e5c6f4fd4001562781e99bbfc7f1f0127187542
      Referenceadded
      —
      https://git.kernel.org/stable/c/6560be3f6a5bb84f006f184f0c966747bb58e1a3
      Referenceadded
      —
      https://git.kernel.org/stable/c/92cda2593cf2ed25b0e9d78e5e6d8303bba1a064
      Referenceadded
      —
      https://git.kernel.org/stable/c/b1e9aef48e4d8a0c1b54fb913077b0824ed7d650
      Referenceadded
      —
      https://git.kernel.org/stable/c/b5107b4ce3ad45fcf369ee2058c8910620f4b5a8
      Referenceadded
      —
      https://git.kernel.org/stable/c/db752ebfdaf2c7f27cd9690ef48b616af068319c

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

    Embed badge

    Show the severity and KEV status of this vulnerability on your site – with a link back here. The image is updated hourly.

    Badge preview for CVE-2026-52930
    <a href="https://intel.neosec.eu/en/cve/CVE-2026-52930"><img src="https://intel.neosec.eu/badge/cve/CVE-2026-52930.svg?lang=en" alt="CVE-2026-52930 – NEOSEC Intel" height="20"></a>