LowCVE-2026-80889

    Linux Kernel: security vulnerability (CVE-2026-80889)

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

    Share

    What is affected, what to do

    Update Linux Kernel to version 5.10.267, Linux Kernel to version 5.15.218, Linux Kernel to version 6.1.185.

    Affected
    • Linux Kernel lt 5.10.265..5.10.267
    • Linux Kernel lt 5.15.216..5.15.218
    • Linux Kernel lt 6.1.183..6.1.185
    • Linux Kernel lt 6.6.148..6.6.151
    • Linux Kernel lt 6.12.101..6.12.103
    • Linux Kernel lt 6.18.40..6.18.44
    • Linux Kernel lt 7.1.5..7.1.8
    Fixed in
    • Linux Kernel 5.10.267
    • Linux Kernel 5.15.218
    • Linux Kernel 6.1.185
    • Linux Kernel 6.6.151
    • Linux Kernel 6.12.103
    • Linux Kernel 6.18.44
    • Linux Kernel 7.1.8

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

    Metrics

    2.5

    XIEM Effective CVSS

    Highest available CVSS rating from NVD and vendor data.

    Source: Vendor (CNA), CVSS v3

    2.5

    CVSS v3

    Severity Low on the scale from 0 to 10.

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

    0.2 %

    EPSS score

    Low — model estimates < 1% exploitation likelihood.

    Source: FIRST EPSS, percentile 7.4

    Show all metrics
    Severity
    Low
    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
    36.80 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
    2.5 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
    2.5
    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
    0.2 %
    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
    7.4
    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:

    can: isotp: fix timer drain order, wakeup handling and tx_gen ordering

    This patch is a follow-up to commit cf070fe33bfb ("can: isotp: serialize TX state transitions under so->rx_lock") which addresses following sashiko-bot findings:

    • isotp_sendmsg(): drain so->txfrtimer first so a stale callback can't re-arm echotimer after the claim

    • isotp_release(): wake so->wait after forcing ISOTP_SHUTDOWN so a sleeping sendmsg() claim isn't stranded

    • isotp_sendmsg(): have both wait_event_interruptible() calls in isotp_sendmsg() also wake on ISOTP_SHUTDOWN and do not return claim to IDLE to avoid corrupting a concurrent isotp_release() process.

    • isotp_sendmsg(): handle potential claim of a new transfer when the wait_event_interruptible() call returns in CAN_ISOTP_WAIT_TX_DONE mode. Don't touch timers and states of the new transfer if a new thread incremented so->tx_gen before getting the lock at err_event_drop.

    • isotp_sendmsg(): handle a stuck can_send() and omit timer and state changes if a new transfer was claimed. wait_tx_done() returns the error recorded in so->tx_result[], tagged with the caller's own generation.

    • isotp_tx_timeout(): on a claimed timeout, record the ECOMM error for the timed-out transfer's own generation in so->tx_result[]; sk->sk_err is raised unconditionally, same as every other error path here.

    • isotp_tx_gen_done()/isotp_tx_timeout(): always read tx.state (acquire) before tx_gen - the reverse order let a weakly ordered CPU pair a fresh tx.state with a stale tx_gen/tx_result slot.

    • isotp_sendmsg(): wait_tx_done: drain sk_err via sock_error() once we have read the result from so->tx_result[], so an already-reported error doesn't stay latched for a later poll()/SO_ERROR.

    Also align the remaining lock-free so->tx.state/rx.state/cfecho accesses and use skb->hash as unique loopback echo frame indicator.

    Source: Ubuntu Security Notices, HKCERT (CC BY 3.0 HK) · HKCERT rating: medium, Debian LTS Advisories, BSI WID Portal, BSI CSAF, ENISA EUVD, cvelistv5, CVE.org (MITRE), 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
    • 6.6.148 – < 6.6.151
    • 6.12.101 – < 6.12.103
    • 5.10.265 – < 5.10.267
    • 6.18.40 – < 6.18.44
    • 7.1.5 – < 7.1.8
    • 6.1.183 – < 6.1.185
    • 5.15.216 – < 5.15.218
    • 6.6.151
    • 6.12.103
    • 5.10.267
    • 6.18.44
    • 7.1.8
    • 6.1.185
    • 5.15.218
    Red HatOpenShift
    • Container Platform
    • —

    Vendors and products

    Affected operating systems

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

    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. ReceivedLinux

      Description added or changed

      Show 10 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Descriptionadded
      —
      In the Linux kernel, the following vulnerability has been resolved: can: isotp: fix timer drain order, wakeup handling and tx_gen ordering This patch is a follow-up to commit cf070fe33bfb ("can: isotp: serialize TX state transitions under so->rx_lock") which addresses following sashiko-bot findings: - isotp_sendmsg(): drain so->txfrtimer first so a stale callback can't re-arm echotimer after the claim - isotp_release(): wake so->wait after forcing ISOTP_SHUTDOWN so a sleeping sendmsg() claim isn't stranded - isotp_sendmsg(): have both wait_event_interruptible() calls in isotp_sendmsg() also wake on ISOTP_SHUTDOWN and do not return claim to IDLE to avoid corrupting a concurrent isotp_release() process. - isotp_sendmsg(): handle potential claim of a new transfer when the wait_event_interruptible() call returns in CAN_ISOTP_WAIT_TX_DONE mode. Don't touch timers and states of the new transfer if a new thread incremented so->tx_gen before getting the lock at err_event_drop. - isotp_sendmsg(): handle a stuck can_send() and omit timer and state changes if a new transfer was claimed. wait_tx_done() returns the error recorded in so->tx_result[], tagged with the caller's own generation. - isotp_tx_timeout(): on a claimed timeout, record the ECOMM error for the timed-out transfer's own generation in so->tx_result[]; sk->sk_err is raised unconditionally, same as every other error path here. - isotp_tx_gen_done()/isotp_tx_timeout(): always read tx.state (acquire) before tx_gen - the reverse order let a weakly ordered CPU pair a fresh tx.state with a stale tx_gen/tx_result slot. - isotp_sendmsg(): wait_tx_done: drain sk_err via sock_error() once we have read the result from so->tx_result[], so an already-reported error doesn't stay latched for a later poll()/SO_ERROR. Also align the remaining lock-free so->tx.state/rx.state/cfecho accesses and use skb->hash as unique loopback echo frame indicator.
      Affected versions (publisher)added
      —
      New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/80xxx/CVE-2026-80889.json">CVE-2026-80889</a>
      Referenceadded
      —
      https://git.kernel.org/stable/c/050f010f920da17c1044a4f174766ad553e770b6
      Referenceadded
      —
      https://git.kernel.org/stable/c/10be509fa8fd95d1e47d40d1f68b0b26dfe9d572
      Referenceadded
      —
      https://git.kernel.org/stable/c/2753722612d8824d3910096f93059f669009b0f0
      Referenceadded
      —
      https://git.kernel.org/stable/c/35c62ac98d06669aa3f0f38b7829eaca929a611e
      Referenceadded
      —
      https://git.kernel.org/stable/c/8acab9fc66d6f426c36968c91a979f70784945a7
      Referenceadded
      —
      https://git.kernel.org/stable/c/af7e25c649ed68cbad07f8185af0f31b892cbf29
      Referenceadded
      —
      https://git.kernel.org/stable/c/bf5c4a8b24acb12739ebb9aea5510b007e4f5239
      Referenceadded
      —
      https://git.kernel.org/stable/c/deca7746b57d982cd4f0301f4443f56780c4a048

      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-2026-80889
    <a href="https://intel.neosec.eu/en/cve/CVE-2026-80889"><img src="https://intel.neosec.eu/badge/cve/CVE-2026-80889.svg?lang=en" alt="CVE-2026-80889 – NEOSEC Intel" height="20"></a>