HighCVE-2026-80792

    Linux Kernel: Use-After-Free (CVE-2026-80792)

    Published Last modified Sources: Red Hat, HKCERT, Ubuntu, Debian LTS, CVE.org, EUVD, Msrc Update Guide, BSI

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    What is affected, what to do

    A flaw was found in the Linux kernel's IPv6 networking stack. A use-after-free vulnerability exists in the `ip6_finish_output2()` function, where a cached pointer to the IPv6 destination address can become stale after memory reallocation.

    Update Linux Kernel to version 5.10.267, Linux Kernel to version 5.5, Linux Kernel to version 5.15.218.

    Affected
    • Linux Kernel lt 5.10.233..5.10.267
    • Linux Kernel lt 5.4.289..5.5
    • Linux Kernel lt 5.15..5.15.218
    • Linux Kernel lt 5.16..6.1.185
    • Linux Kernel lt 6.2..6.6.154
    • Linux Kernel lt 6.7..6.12.106
    • Linux Kernel lt 6.13..6.18.47
    • Linux Kernel lt 6.19..7.1.11
    • Linux Kernel lt 7.2..7.2.1
    Fixed in
    • Linux Kernel 5.10.267
    • Linux Kernel 5.5
    • Linux Kernel 5.15.218
    • Linux Kernel 6.1.185
    • Linux Kernel 6.6.154
    • Linux Kernel 6.12.106
    • Linux Kernel 6.18.47
    • Linux Kernel 7.1.11
    • Linux Kernel 7.2.1
    • Linux Kernel 7.3

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

    Metrics

    8.1

    XIEM Effective CVSS

    Highest available CVSS rating from NVD and vendor data.

    Source: Vendor (CNA), CVSS v3

    8.1

    CVSS v3

    Severity High on the scale from 0 to 10.

    Source: Red Hat, HKCERT, Ubuntu, Debian LTS, CVE.org, EUVD, Msrc Update Guide, BSI

    0.2 %

    EPSS score

    Low — model estimates < 1% exploitation likelihood.

    Source: FIRST EPSS, percentile 9.3

    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
    65.26 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
    8.1 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
    8.1
    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
    0.2 %
    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
    9.3
    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
    CISA assessment (SSVC)
    Exploitation: none known · not automatable · Technical impact: partial
    Source: CISA Vulnrichment, as of 6 November 2026

    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 networking stack. A use-after-free vulnerability exists in the `ip6_finish_output2()` function, where a cached pointer to the IPv6 destination address can become stale after memory reallocation. An attacker could potentially exploit this to leak sensitive kernel data, misdirect network traffic, or cause a system crash (Denial of Service).

    Source: redhat_csaf, HKCERT (CC BY 3.0 HK) · HKCERT rating: medium, Ubuntu Security Notices, Debian LTS Advisories, cvelistv5, ENISA EUVD, NVD (NIST), CVE.org (MITRE), Microsoft Security Update Guide, 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
    • 7.2 – < 7.2.1
    • 6.2 – < 6.6.154
    • 5.15 – < 5.15.218
    • 5.10.233 – < 5.10.267
    • 6.7 – < 6.12.106
    • —
    • 6.13 – < 6.18.47
    • 5.4.289 – < 5.5
    • 6.19 – < 7.1.11
    • 5.16 – < 6.1.185
    • 7.2.1
    • 6.6.154
    • 5.15.218
    • 5.10.267
    • 6.12.106
    • 7.3
    • 6.18.47
    • 5.5
    • 7.1.11
    • 6.1.185
    Red HatOpenShift
    • Container Platform
    • —

    Vendors and products

    Affected operating systems

    Affected operating systems
    Linuxdebianlinuxbookworm
    Linuxubuntulinuxjammy
    Linuxubuntulinuxnoble
    Linuxubuntulinuxresolute
    Linuxdebianlinux-6.12bookworm
    Linuxubuntulinux-awsjammy
    Linuxubuntulinux-awsnoble
    Linuxubuntulinux-awsresolute
    Linuxubuntulinux-aws-5.15focal
    Linuxubuntulinux-aws-6.8jammy
    Linuxubuntulinux-aws-7.0noble
    Linuxubuntulinux-aws-fipsjammy
    Linuxubuntulinux-aws-fipsnoble
    Linuxubuntulinux-azurejammy
    Linuxubuntulinux-azurenoble
    Linuxubuntulinux-azureresolute
    Linuxubuntulinux-azure-5.15focal
    Linuxubuntulinux-azure-6.8jammy
    Linuxubuntulinux-azure-fdejammy
    Linuxubuntulinux-azure-fdenoble
    Linuxubuntulinux-azure-fderesolute
    Linuxubuntulinux-azure-fde-5.15focal
    Linuxubuntulinux-azure-fde-6.8jammy
    Linuxubuntulinux-azure-fde-7.0noble

    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

      CISA assessment (SSVC): exploitation: none known, automatable: no

      Show the original change
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      SSVC assessmentadded
      —
      {"id":"CVE-2026-80792","role":"CISA Coordinator","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"partial"}],"version":"2.0.3","timestamp":"2026-11-06T17:03:27.127514Z"}

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

    2. Record modifiedLinux

      1 individual change: Affected versions (publisher)

      Show the original change
      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/2026/80xxx/CVE-2026-80792.json">CVE-2026-80792</a>

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

    3. ReceivedLinux

      Description added or changed

      Show 11 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Descriptionadded
      —
      In the Linux kernel, the following vulnerability has been resolved: ipv6: fix use-after-free in ip6_finish_output2() ip6_finish_output2() caches a pointer to the IPv6 destination address (daddr) before invoking lwtunnel_xmit(). The LWT-BPF transmit path or other encapsulation operations within lwtunnel_xmit() can reallocate the skb head, freeing the memory that daddr points to. When lwtunnel_xmit() returns LWTUNNEL_XMIT_CONTINUE, the function continues to use the stale daddr pointer to compute the nexthop and to look up or create the neighbour entry. This results in a use-after-free read, which can leak sensitive kernel data, pollute the neighbour table with arbitrary values, misdirect traffic, or crash the system. Fix this by re-fetching the IPv6 header and the destination address pointer after lwtunnel_xmit() returns LWTUNNEL_XMIT_CONTINUE, ensuring that the subsequent nexthop computation and neighbour lookup operate on valid memory.
      Affected versions (publisher)added
      —
      New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/80xxx/CVE-2026-80792.json">CVE-2026-80792</a>
      Referenceadded
      —
      https://git.kernel.org/stable/c/087ee0d914aaae929f1660c9ca878e367655ba1a
      Referenceadded
      —
      https://git.kernel.org/stable/c/3c770ac4e6f07af7c7b40c474a3efc61ffed7862
      Referenceadded
      —
      https://git.kernel.org/stable/c/3dc98e5fe82d069dd29b124ffbdb679331dfea43
      Referenceadded
      —
      https://git.kernel.org/stable/c/73a187384a8c8b983c7fea046d716b6752a1e7a3
      Referenceadded
      —
      https://git.kernel.org/stable/c/75e0a544ebe9af663ef53ca21e9e9185c51fb54a
      Referenceadded
      —
      https://git.kernel.org/stable/c/99219c82804f266189388e8bf1cf5135d10d5515
      Referenceadded
      —
      https://git.kernel.org/stable/c/c95f01b78266828a57060d754fcbfc92123a98ed
      Referenceadded
      —
      https://git.kernel.org/stable/c/d0d48d999b0eee6bb176ef4e39d9be868fa80f7e
      Referenceadded
      —
      https://git.kernel.org/stable/c/d960881b9312e781a3429aabceb223ce6b7c882f

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

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