CriticalCVE-2026-63922

    Linux Kernel: Use After Free (CVE-2026-63922)

    Published Last modified Sources: SUSE, Ubuntu, Red Hat, CVE.org, BSI

    What is affected, what to do

    A flaw was found in the Linux kernel's IPv6 extension header processing. When processing the Home Address Option (HAO), the cached network header pointer may become invalid if the packet's memory is reallocated.

    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 2.6.19..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..6.12.93
    • Linux Kernel lt 6.13..6.18.35
    • Linux Kernel lt 6.19..7.0.12
    Fixed in
    • Linux Kernel 5.10.259
    • Linux Kernel 5.15.210
    • Linux Kernel 6.1.176
    • Linux Kernel 6.6.143
    • Linux Kernel 6.12.93
    • Linux Kernel 6.18.35
    • Linux Kernel 7.0.12
    • Linux Kernel 7.1

    Not sure whether and how you are affected? Ask a question about this vulnerability

    Metrics

    9.8

    Priority

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

    Source: NVD, CVSS v3

    9.8

    CVSS v3

    Severity Critical on the scale from 0 to 10.

    Source: SUSE, Ubuntu, Red Hat, CVE.org, BSI

    0.7 %

    EPSS score

    Low — model estimates < 1% exploitation likelihood.

    Source: FIRST EPSS, percentile 53.6

    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
    93.00 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
    9.8 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
    9.8
    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
    0.7 %
    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
    53.6
    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: total
    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-416

    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

    A flaw was found in the Linux kernel's IPv6 extension header processing. When processing the Home Address Option (HAO), the cached network header pointer may become invalid if the packet's memory is reallocated. This can lead to incorrect parsing of subsequent IPv6 Type-Length-Value (TLV) options, potentially causing unexpected network behavior or a denial of service.

    Source: suse_csaf, Ubuntu Security Notices, redhat_csaf, NVD (NIST), cvelistv5, 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
    • 6.13 – < 6.18.35
    • 6.7 – < 6.12.93
    • 5.11 – < 5.15.210
    • 6.19 – < 7.0.12
    • —
    • 2.6.19 – < 5.10.259
    • 5.16 – < 6.1.176
    • 6.2 – < 6.6.143
    • 6.18.35
    • 6.12.93
    • 5.15.210
    • 7.0.12
    • 7.1
    • 5.10.259
    • 6.1.176
    • 6.6.143

    Vendors and products

    Affected operating systems

    Affected operating systems
    Linuxubuntulinuxnoble
    Linuxubuntulinux-azurenoble
    Linuxubuntulinux-azure-6.8jammy
    Linuxubuntulinux-azure-fdenoble
    Linuxubuntulinux-azure-fde-6.8jammy
    Linuxubuntulinux-azure-fipsnoble
    Linuxubuntulinux-fipsnoble
    Linuxubuntulinux-gcpnoble
    Linuxubuntulinux-gcp-6.8jammy
    Linuxubuntulinux-gcp-fipsnoble
    Linuxubuntulinux-gkenoble
    Linuxubuntulinux-gkeopnoble
    Linuxubuntulinux-ibmnoble
    Linuxubuntulinux-lowlatencynoble
    Linuxubuntulinux-lowlatency-hwe-6.8jammy
    Linuxubuntulinux-oraclenoble
    Linuxubuntulinux-oracle-6.8jammy
    Linuxubuntulinux-raspinoble
    Linuxubuntulinux-raspi-realtimenoble
    Linuxubuntulinux-realtimenoble
    Linuxubuntulinux-realtime-6.8jammy
    Linuxlinuxlinux_kernel7.1
    Linuxlinuxlinux_kernel—

    Weakness classes (CWE)

    • CWE-416Use After Free

      Variant

      The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.

      Entry at MITRE CWE-416

    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. Initial analysis by NVDNVD

      Newly listed as affected:
      • Linux Kernel (5.16 – before 6.1.176; 6.13 – before 6.18.35; 6.2 – before 6.6.143; 6.7 – before 6.12.93; 5.11 – before 5.15.210; 6.19 – before 7.0.12; 2.6.19 – before 5.10.259; 5 individual versions)
      Show 9 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      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) 6.13 up to (excluding) 6.18.35 *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) 6.7 up to (excluding) 6.12.93 *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:7.1:rc5:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.19 up to (excluding) 7.0.12 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 2.6.19 up to (excluding) 5.10.259
      Reference typeadded
      —
      kernel.org: https://git.kernel.org/stable/c/12d957979e4a800167842f1b42be6a606d227ebe Types: Patch
      Reference typeadded
      —
      kernel.org: https://git.kernel.org/stable/c/1a11eb7431e3d2882f5bd5939c5a9bbc65ccf4d1 Types: Patch
      Reference typeadded
      —
      kernel.org: https://git.kernel.org/stable/c/751db1b802a067b7fff25880f4e9f9152a171538 Types: Patch
      Reference typeadded
      —
      kernel.org: https://git.kernel.org/stable/c/9b6dcc0a39fd71752937f0b6b3973e1416085dcf Types: Patch
      Reference typeadded
      —
      kernel.org: https://git.kernel.org/stable/c/b3ac54e5c905f86d22b502eacb5686a282c5659f Types: Patch
      Reference typeadded
      —
      kernel.org: https://git.kernel.org/stable/c/f7b52afe3592eae66e160586b45a3f2242972c63 Types: Patch
      Reference typeadded
      —
      kernel.org: https://git.kernel.org/stable/c/f8aabed3ff3e986920cf02a2a2785e08e586b234 Types: Patch
      Reference typeadded
      —
      kernel.org: https://git.kernel.org/stable/c/ff375ed1cba81392346c5bfbf0bb7a13b2946f99 Types: Patch

      Source identifier: nvd@nist.gov

    2. Record modifiedCISA ADP

      Weakness type: CWE-416

      Show the original change
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Weakness type (CWE)added
      —
      CWE-416

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

    3. Record modifiedLinux

      Show 16 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Referenceadded
      —
      https://git.kernel.org/stable/c/12d957979e4a800167842f1b42be6a606d227ebe
      Referenceadded
      —
      https://git.kernel.org/stable/c/1a11eb7431e3d2882f5bd5939c5a9bbc65ccf4d1
      Referenceadded
      —
      https://git.kernel.org/stable/c/751db1b802a067b7fff25880f4e9f9152a171538
      Referenceadded
      —
      https://git.kernel.org/stable/c/9b6dcc0a39fd71752937f0b6b3973e1416085dcf
      Referenceadded
      —
      https://git.kernel.org/stable/c/b3ac54e5c905f86d22b502eacb5686a282c5659f
      Referenceadded
      —
      https://git.kernel.org/stable/c/f7b52afe3592eae66e160586b45a3f2242972c63
      Referenceadded
      —
      https://git.kernel.org/stable/c/f8aabed3ff3e986920cf02a2a2785e08e586b234
      Referenceadded
      —
      https://git.kernel.org/stable/c/ff375ed1cba81392346c5bfbf0bb7a13b2946f99
      Referenceremoved
      https://git.kernel.org/stable/c/12d957979e4a800167842f1b42be6a606d227ebe
      —
      Referenceremoved
      https://git.kernel.org/stable/c/1a11eb7431e3d2882f5bd5939c5a9bbc65ccf4d1
      —
      Referenceremoved
      https://git.kernel.org/stable/c/751db1b802a067b7fff25880f4e9f9152a171538
      —
      Referenceremoved
      https://git.kernel.org/stable/c/9b6dcc0a39fd71752937f0b6b3973e1416085dcf
      —
      Referenceremoved
      https://git.kernel.org/stable/c/b3ac54e5c905f86d22b502eacb5686a282c5659f
      —
      Referenceremoved
      https://git.kernel.org/stable/c/f7b52afe3592eae66e160586b45a3f2242972c63
      —
      Referenceremoved
      https://git.kernel.org/stable/c/f8aabed3ff3e986920cf02a2a2785e08e586b234
      —
      Referenceremoved
      https://git.kernel.org/stable/c/ff375ed1cba81392346c5bfbf0bb7a13b2946f99
      —

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

    4. 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-2026-63922","role":"CISA Coordinator","options":[{"exploitation":"none"},{"automatable":"yes"},{"technicalImpact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T15:33:28.158927Z"}

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

    5. Record modifiedLinux

      Show 2 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Referenceadded
      —
      https://git.kernel.org/stable/c/b3ac54e5c905f86d22b502eacb5686a282c5659f
      Affected versions (publisher)changed
      Linux, Linux
      Linux, Linux

      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-2026-63922
    <a href="https://intel.neosec.eu/en/cve/CVE-2026-63922"><img src="https://intel.neosec.eu/badge/cve/CVE-2026-63922.svg?lang=en" alt="CVE-2026-63922 – NEOSEC Intel" height="20"></a>