CriticalCVE-2026-53225

    Linux Kernel: Use of Uninitialized Memory (CVE-2026-53225)

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

    What is affected, what to do

    In the Linux kernel, the following vulnerability has been resolved: sctp: fix uninit-value in __sctp_rcv_asconf_lookup() __sctp_rcv_asconf_lookup() in net/sctp/input.c only checks that the ASCONF chunk can hold the ADDIP header and a parameter header, then calls af->from_addr_param(), which reads the full address (16 bytes for IPv6) trusting the parameter's declared length. An unauthenticated peer can send a truncated trailing ASCONF chunk that declares an IPv6 address parameter but stops after the 4-byte parameter header; reached from the no-association lookup path, from_addr_param() then reads uninitialized bytes past the parameter.

    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 2.6.25..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

    9.1

    Priority

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

    Source: Vendor (CNA), CVSS v3

    9.1

    CVSS v3

    Severity Critical on the scale from 0 to 10.

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

    0.6 %

    EPSS score

    Low — model estimates < 1% exploitation likelihood.

    Source: FIRST EPSS, percentile 47.5

    Show all metrics
    Severity
    Critical
    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
    82.96 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
    9.1 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
    9.1
    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
    0.6 %
    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
    47.5
    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-125

    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: fix uninit-value in __sctp_rcv_asconf_lookup() __sctp_rcv_asconf_lookup() in net/sctp/input.c only checks that the ASCONF chunk can hold the ADDIP header and a parameter header, then calls af->from_addr_param(), which reads the full address (16 bytes for IPv6) trusting the parameter's declared length. An unauthenticated peer can send a truncated trailing ASCONF chunk that declares an IPv6 address parameter but stops after the 4-byte parameter header; reached from the no-association lookup path, from_addr_param() then reads uninitialized bytes past the parameter. Impact: an unauthenticated SCTP peer makes the receive path read up to 16 bytes of uninitialized memory past a truncated ASCONF address parameter. The sibling __sctp_rcv_init_lookup() bounds parameters with sctp_walk_params(); this path open-codes the fetch and omits the bound. Verify the whole address parameter lies within the chunk before from_addr_param() reads it, the same class of fix as commit 51e5ad549c43 ("net: sctp: fix KMSAN uninit-value in sctp_inq_pop").

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

    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
    • 2.6.25 – < 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-125Out-of-bounds Read

      Base

      The product reads data past the end, or before the beginning, of the intended buffer.

      Entry at MITRE CWE-125

    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-125

      Show the original change
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Weakness type (CWE)added
      —
      CWE-125

      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-2026-53225","role":"CISA Coordinator","options":[{"exploitation":"none"},{"automatable":"yes"},{"technicalImpact":"partial"}],"version":"2.0.3","timestamp":"2026-10-16T15:27:14.365296Z"}

      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/446e0ecd845abc394b24ae2030a883572bec9d16
      Referenceadded
      —
      https://git.kernel.org/stable/c/8ce96f1182644079249a24ac7e2ffc32e0301a46
      Referenceadded
      —
      https://git.kernel.org/stable/c/8e86817b8af4d552f3c6fe04ca52bb0c8c57411d
      Referenceadded
      —
      https://git.kernel.org/stable/c/928dd94db23e8ba340f83d68f7f24d831b7a4426
      Referenceadded
      —
      https://git.kernel.org/stable/c/d6bd0bb7697ea8c0387b0d9d973453f479017b23
      Referenceadded
      —
      https://git.kernel.org/stable/c/d796cfd06074b579d265b28401306cadd30db945
      Referenceadded
      —
      https://git.kernel.org/stable/c/f76a8b323e28e0951f979dbef20a7496383c47df
      Referenceadded
      —
      https://git.kernel.org/stable/c/f8373d7090b745728de66308deeecc67e8d319ce
      Referenceremoved
      https://git.kernel.org/stable/c/446e0ecd845abc394b24ae2030a883572bec9d16
      —
      Referenceremoved
      https://git.kernel.org/stable/c/8ce96f1182644079249a24ac7e2ffc32e0301a46
      —
      Referenceremoved
      https://git.kernel.org/stable/c/8e86817b8af4d552f3c6fe04ca52bb0c8c57411d
      —
      Referenceremoved
      https://git.kernel.org/stable/c/928dd94db23e8ba340f83d68f7f24d831b7a4426
      —
      Referenceremoved
      https://git.kernel.org/stable/c/d6bd0bb7697ea8c0387b0d9d973453f479017b23
      —
      Referenceremoved
      https://git.kernel.org/stable/c/d796cfd06074b579d265b28401306cadd30db945
      —
      Referenceremoved
      https://git.kernel.org/stable/c/f76a8b323e28e0951f979dbef20a7496383c47df
      —
      Referenceremoved
      https://git.kernel.org/stable/c/f8373d7090b745728de66308deeecc67e8d319ce
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/446e0ecd845abc394b24ae2030a883572bec9d16 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/8ce96f1182644079249a24ac7e2ffc32e0301a46 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/8e86817b8af4d552f3c6fe04ca52bb0c8c57411d Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/928dd94db23e8ba340f83d68f7f24d831b7a4426 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/d6bd0bb7697ea8c0387b0d9d973453f479017b23 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/d796cfd06074b579d265b28401306cadd30db945 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/f76a8b323e28e0951f979dbef20a7496383c47df Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/f8373d7090b745728de66308deeecc67e8d319ce 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/2026/53xxx/CVE-2026-53225.json">CVE-2026-53225</a>
      Referenceadded
      —
      https://cert-portal.siemens.com/productcert/html/ssa-784472.html

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

    5. Initial analysis by NVDNVD

      Newly listed as affected:
      • Linux Kernel (5.16 – before 6.1.176; 6.2 – before 6.6.143; 5.11 – before 5.15.210; 6.13 – before 6.18.36; 6.7 – before 6.12.94; 6.19 – before 7.0.13; 2.6.25 – before 5.10.259; 7 individual versions)

      Weakness type: CWE-908

      Show 10 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Weakness type (CWE)added
      —
      CWE-908
      Product configurationadded
      —
      OR *cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.16 up to (excluding) 6.1.176 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.2 up to (excluding) 6.6.143 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.11 up to (excluding) 5.15.210 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.13 up to (excluding) 6.18.36 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.7 up to (excluding) 6.12.94 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.19 up to (excluding) 7.0.13 *cpe:2.3:o:linux:linux_kernel:7.1:rc5:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:7.1:rc6:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:7.1:rc7:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 2.6.25 up to (excluding) 5.10.259
      Reference typeadded
      —
      kernel.org: https://git.kernel.org/stable/c/446e0ecd845abc394b24ae2030a883572bec9d16 Types: Patch
      Reference typeadded
      —
      kernel.org: https://git.kernel.org/stable/c/8ce96f1182644079249a24ac7e2ffc32e0301a46 Types: Patch
      Reference typeadded
      —
      kernel.org: https://git.kernel.org/stable/c/8e86817b8af4d552f3c6fe04ca52bb0c8c57411d Types: Patch
      Reference typeadded
      —
      kernel.org: https://git.kernel.org/stable/c/928dd94db23e8ba340f83d68f7f24d831b7a4426 Types: Patch
      Reference typeadded
      —
      kernel.org: https://git.kernel.org/stable/c/d6bd0bb7697ea8c0387b0d9d973453f479017b23 Types: Patch
      Reference typeadded
      —
      kernel.org: https://git.kernel.org/stable/c/d796cfd06074b579d265b28401306cadd30db945 Types: Patch
      Reference typeadded
      —
      kernel.org: https://git.kernel.org/stable/c/f76a8b323e28e0951f979dbef20a7496383c47df Types: Patch
      Reference typeadded
      —
      kernel.org: https://git.kernel.org/stable/c/f8373d7090b745728de66308deeecc67e8d319ce Types: Patch

      Source identifier: nvd@nist.gov

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