HighCVE-2026-52929

    Linux Kernel: NULL Pointer Dereference (CVE-2026-52929)

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

    What is affected, what to do

    In the Linux kernel, the following vulnerability has been resolved: sctp: stream: fully roll back denied add-stream state When ADD_OUT_STREAMS is denied, SCTP only shrinks the queued chunks and then lowers outcnt. That leaves removed stream metadata behind, so a later re-add can reuse a stale ext and hit a null-pointer dereference in the scheduler get path.

    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 4.15..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

    7.5

    Priority

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

    Source: Vendor (CNA), CVSS v3

    7.5

    CVSS v3

    Severity High on the scale from 0 to 10.

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

    0.9 %

    EPSS score

    Low — model estimates < 1% exploitation likelihood.

    Source: FIRST EPSS, percentile 58.9

    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
    84.51 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
    7.5 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
    7.5
    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
    0.9 %
    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
    58.9
    High — this CVE ranks above the median of all CVEs scored today (rank ≥ 36%).
    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 · automatable · Technical impact: partial
    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-476

    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: sctp: stream: fully roll back denied add-stream state When ADD_OUT_STREAMS is denied, SCTP only shrinks the queued chunks and then lowers outcnt. That leaves removed stream metadata behind, so a later re-add can reuse a stale ext and hit a null-pointer dereference in the scheduler get path. Fix the rollback by tearing down the removed stream state the same way other stream resizes do. Unschedule the current scheduler state, drop the removed stream ext state with sctp_stream_outq_migrate(), and then reschedule the remaining streams. This keeps scheduler-private RR/FC/PRIO lists consistent while fully rolling back denied outgoing stream additions.

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

    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
    • 4.15 – < 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
    Linuxlinuxlinux_kernel7.1
    Linuxlinuxlinux_kernel—

    Weakness classes (CWE)

    • CWE-476NULL Pointer Dereference

      Base

      The product dereferences a pointer that it expects to be valid but is NULL.

      Entry at MITRE CWE-476

    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-476

      Show the original change
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Weakness type (CWE)added
      —
      CWE-476

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

    2. Record modifiedCISA ADP

      CISA assessment (SSVC): exploitation: none known, automatable: yes

      Show the original change
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      SSVC assessmentadded
      —
      {"id":"CVE-2026-52929","role":"CISA Coordinator","options":[{"exploitation":"none"},{"automatable":"yes"},{"technicalImpact":"partial"}],"version":"2.0.3","timestamp":"2026-10-16T15:22:54.348092Z"}

      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/0cd2dc6dce8ca47212cd306ccd52eb315ef3cf85
      Referenceadded
      —
      https://git.kernel.org/stable/c/1c6773b8c081509dcd5cd2954f2b02c50c00f151
      Referenceadded
      —
      https://git.kernel.org/stable/c/39dc2b0eb5371a669ebc9ec6072b9184eac95418
      Referenceadded
      —
      https://git.kernel.org/stable/c/7dd9a42b044aad2dbe037db1c1e2943582485b44
      Referenceadded
      —
      https://git.kernel.org/stable/c/9662eb0401518f0b4681f10e7fbf688f504f24cf
      Referenceadded
      —
      https://git.kernel.org/stable/c/a5f8a90ac9f77c678a9781c0a464b635e0d63e49
      Referenceadded
      —
      https://git.kernel.org/stable/c/a6724b7b812ac8793514a1d5938db5d9d29ae725
      Referenceadded
      —
      https://git.kernel.org/stable/c/d5ea0b3e261fcb2cfff142675516165244cab1da
      Referenceremoved
      https://git.kernel.org/stable/c/0cd2dc6dce8ca47212cd306ccd52eb315ef3cf85
      —
      Referenceremoved
      https://git.kernel.org/stable/c/1c6773b8c081509dcd5cd2954f2b02c50c00f151
      —
      Referenceremoved
      https://git.kernel.org/stable/c/39dc2b0eb5371a669ebc9ec6072b9184eac95418
      —
      Referenceremoved
      https://git.kernel.org/stable/c/7dd9a42b044aad2dbe037db1c1e2943582485b44
      —
      Referenceremoved
      https://git.kernel.org/stable/c/9662eb0401518f0b4681f10e7fbf688f504f24cf
      —
      Referenceremoved
      https://git.kernel.org/stable/c/a5f8a90ac9f77c678a9781c0a464b635e0d63e49
      —
      Referenceremoved
      https://git.kernel.org/stable/c/a6724b7b812ac8793514a1d5938db5d9d29ae725
      —
      Referenceremoved
      https://git.kernel.org/stable/c/d5ea0b3e261fcb2cfff142675516165244cab1da
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/0cd2dc6dce8ca47212cd306ccd52eb315ef3cf85 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/1c6773b8c081509dcd5cd2954f2b02c50c00f151 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/39dc2b0eb5371a669ebc9ec6072b9184eac95418 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/7dd9a42b044aad2dbe037db1c1e2943582485b44 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/9662eb0401518f0b4681f10e7fbf688f504f24cf Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/a5f8a90ac9f77c678a9781c0a464b635e0d63e49 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/a6724b7b812ac8793514a1d5938db5d9d29ae725 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/d5ea0b3e261fcb2cfff142675516165244cab1da 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/2026/52xxx/CVE-2026-52929.json">CVE-2026-52929</a>
      Referenceadded
      —
      https://cert-portal.siemens.com/productcert/html/ssa-784472.html

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

    5. 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: sctp: stream: fully roll back denied add-stream state When ADD_OUT_STREAMS is denied, SCTP only shrinks the queued chunks and then lowers outcnt. That leaves removed stream metadata behind, so a later re-add can reuse a stale ext and hit a null-pointer dereference in the scheduler get path. Fix the rollback by tearing down the removed stream state the same way other stream resizes do. Unschedule the current scheduler state, drop the removed stream ext state with sctp_stream_outq_migrate(), and then reschedule the remaining streams. This keeps scheduler-private RR/FC/PRIO lists consistent while fully rolling back denied outgoing stream additions.
      Referenceadded
      —
      https://git.kernel.org/stable/c/0cd2dc6dce8ca47212cd306ccd52eb315ef3cf85
      Referenceadded
      —
      https://git.kernel.org/stable/c/1c6773b8c081509dcd5cd2954f2b02c50c00f151
      Referenceadded
      —
      https://git.kernel.org/stable/c/39dc2b0eb5371a669ebc9ec6072b9184eac95418
      Referenceadded
      —
      https://git.kernel.org/stable/c/7dd9a42b044aad2dbe037db1c1e2943582485b44
      Referenceadded
      —
      https://git.kernel.org/stable/c/9662eb0401518f0b4681f10e7fbf688f504f24cf
      Referenceadded
      —
      https://git.kernel.org/stable/c/a5f8a90ac9f77c678a9781c0a464b635e0d63e49
      Referenceadded
      —
      https://git.kernel.org/stable/c/a6724b7b812ac8793514a1d5938db5d9d29ae725
      Referenceadded
      —
      https://git.kernel.org/stable/c/d5ea0b3e261fcb2cfff142675516165244cab1da

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

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