MediumCVE-2026-80846

    Linux Kernel: security vulnerability (CVE-2026-80846)

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

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    What is affected, what to do

    In the Linux kernel, the following vulnerability has been resolved: xfrm: drop ESP-in-TCP packets with no ingress device ESP-in-TCP receives records through the TCP strparser. handle_esp() restores skb->dev from the saved skb_iif before passing the packet into the XFRM input path. Queued TCP data can be processed after the original ingress device has been removed, for example during veth or net namespace teardown.

    Update Linux Kernel to version 5.10.269, Linux Kernel to version 5.15.220, Linux Kernel to version 6.1.187.

    Affected
    • Linux Kernel lt 5.6..5.10.269
    • Linux Kernel lt 5.11..5.15.220
    • Linux Kernel lt 5.16..6.1.187
    • Linux Kernel lt 6.2..6.6.156
    • Linux Kernel lt 6.7..6.12.108
    • Linux Kernel lt 6.13..6.18.49
    • Linux Kernel lt 6.19..7.1.13
    • Linux Kernel lt 7.2..7.2.3
    Fixed in
    • Linux Kernel 5.10.269
    • Linux Kernel 5.15.220
    • Linux Kernel 6.1.187
    • Linux Kernel 6.6.156
    • Linux Kernel 6.12.108
    • Linux Kernel 6.18.49
    • Linux Kernel 7.1.13
    • Linux Kernel 7.2.3
    • Linux Kernel 7.3

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

    Metrics

    5.9

    XIEM Effective CVSS

    Highest available CVSS rating from NVD and vendor data.

    Source: Vendor (CNA), CVSS v3

    5.9

    CVSS v3

    Severity Medium on the scale from 0 to 10.

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

    0.2 %

    EPSS score

    Low — model estimates < 1% exploitation likelihood.

    Source: FIRST EPSS, percentile 9.3

    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
    54.06 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
    5.9 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
    5.9
    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

    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: xfrm: drop ESP-in-TCP packets with no ingress device ESP-in-TCP receives records through the TCP strparser. handle_esp() restores skb->dev from the saved skb_iif before passing the packet into the XFRM input path. Queued TCP data can be processed after the original ingress device has been removed, for example during veth or net namespace teardown. In that case dev_get_by_index_rcu() returns NULL. The XFRM IPv4 and IPv6 input paths both expect skb->dev to be valid while building the route lookup, so queued ESP-in-TCP data can dereference a NULL device. Drop the packet if the saved ingress device can no longer be resolved. Such a packet can no longer be routed through the normal XFRM receive path, and this preserves the existing behaviour for packets whose ingress device still exists.

    Source: Ubuntu Security Notices, HKCERT (CC BY 3.0 HK) · HKCERT rating: medium, suse_csaf, Debian LTS Advisories, Debian Security Advisories, ENISA EUVD, cvelistv5, 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
    • 6.13 – < 6.18.49
    • 5.11 – < 5.15.220
    • 5.16 – < 6.1.187
    • 6.7 – < 6.12.108
    • 7.2 – < 7.2.3
    • —
    • 5.6 – < 5.10.269
    • 6.19 – < 7.1.13
    • 6.2 – < 6.6.156
    • 6.18.49
    • 5.15.220
    • 6.1.187
    • 6.12.108
    • 7.2.3
    • 7.3
    • 5.10.269
    • 7.1.13
    • 6.6.156
    Red HatOpenShift
    • Container Platform
    • —

    Vendors and products

    Affected operating systems

    Affected operating systems
    Linuxdebianlinuxbookworm
    Linuxdebianlinuxtrixie
    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

    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 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-2026-80846.json">CVE-2026-80846</a>

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

    2. 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: xfrm: drop ESP-in-TCP packets with no ingress device ESP-in-TCP receives records through the TCP strparser. handle_esp() restores skb->dev from the saved skb_iif before passing the packet into the XFRM input path. Queued TCP data can be processed after the original ingress device has been removed, for example during veth or net namespace teardown. In that case dev_get_by_index_rcu() returns NULL. The XFRM IPv4 and IPv6 input paths both expect skb->dev to be valid while building the route lookup, so queued ESP-in-TCP data can dereference a NULL device. Drop the packet if the saved ingress device can no longer be resolved. Such a packet can no longer be routed through the normal XFRM receive path, and this preserves the existing behaviour for packets whose ingress device still exists.
      Affected versions (publisher)added
      —
      New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/80xxx/CVE-2026-80846.json">CVE-2026-80846</a>
      Referenceadded
      —
      https://git.kernel.org/stable/c/239d0f71af09dc2029fd4d730cb24b8c83aaa43a
      Referenceadded
      —
      https://git.kernel.org/stable/c/2dd1609cadff46c4b20ce53b91ab9cce1380456a
      Referenceadded
      —
      https://git.kernel.org/stable/c/328e40aa774b446969c69b654c52a051a95af8a1
      Referenceadded
      —
      https://git.kernel.org/stable/c/6af5cdb03819a5ce6e945992635c6c5e91045367
      Referenceadded
      —
      https://git.kernel.org/stable/c/7911e0236616487b89db6bd3ba3f408abd10eb23
      Referenceadded
      —
      https://git.kernel.org/stable/c/943d95233b8b4a88994e244fcf466f8c403d63f1
      Referenceadded
      —
      https://git.kernel.org/stable/c/c296d25efbc840be24de83f56d43bc47e714ace9
      Referenceadded
      —
      https://git.kernel.org/stable/c/e1d7c5ac1c246ce5775f604515de0a59fbf2116e
      Referenceadded
      —
      https://git.kernel.org/stable/c/f00235f9d12301183d61f75fbe4105506f3e5140

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

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