Not ratedCVE-2026-100081

    Linux Kernel: security vulnerability (CVE-2026-100081)

    Published Last modified Sources: CVE.org

    Share

    What is affected, what to do

    In the Linux kernel, the following vulnerability has been resolved: xen-netback: defer xenvif_mcast_addr_list_free() In order for the function to legitimately avoid locking/RCU, it needs to run after all TX/RX processing has finished/stopped: Lookups happen from xenvif_start_xmit(), while adds/removes happen from xenvif_tx_action() (called out of xenvif_poll()). Move the call out of xenvif_disconnect_data() (the call to the function from connect()'s error path doesn't require any cleaning up there), and put it past the synchronization point in backend_disconnect().

    Update Linux Kernel to version 5.10.274, Linux Kernel to version 5.15.225, Linux Kernel to version 6.1.192.

    Affected
    • Linux Kernel lt 4.11..5.10.274
    • Linux Kernel lt 5.11..5.15.225
    • Linux Kernel lt 5.16..6.1.192
    • Linux Kernel lt 6.2..6.6.162
    • Linux Kernel lt 6.7..6.12.116
    • Linux Kernel lt 6.13..6.18.62
    • Linux Kernel lt 6.19..7.3.3
    Fixed in
    • Linux Kernel 5.10.274
    • Linux Kernel 5.15.225
    • Linux Kernel 6.1.192
    • Linux Kernel 6.6.162
    • Linux Kernel 6.12.116
    • Linux Kernel 6.18.62
    • Linux Kernel 7.3.3

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

    Metrics

    —

    Priority

    No value is available for this vulnerability.

    —

    CVSS v3

    No value is available for this vulnerability.

    0.2 %

    EPSS score

    Low — model estimates < 1% exploitation likelihood.

    Source: FIRST EPSS, percentile 15.7

    Show all metrics
    Severity
    Not rated
    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
    31.97 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
    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
    15.7
    Elevated — this CVE ranks above at least 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: xen-netback: defer xenvif_mcast_addr_list_free() In order for the function to legitimately avoid locking/RCU, it needs to run after all TX/RX processing has finished/stopped: Lookups happen from xenvif_start_xmit(), while adds/removes happen from xenvif_tx_action() (called out of xenvif_poll()). Move the call out of xenvif_disconnect_data() (the call to the function from connect()'s error path doesn't require any cleaning up there), and put it past the synchronization point in backend_disconnect(). This is XSA-527 / CVE-2026-100081.

    Source: cvelistv5, NVD (NIST)

    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
    • 6.19 – < 7.3.3
    • 5.16 – < 6.1.192
    • 6.2 – < 6.6.162
    • 4.11 – < 5.10.274
    • 6.7 – < 6.12.116
    • 6.13 – < 6.18.62
    • 5.11 – < 5.15.225
    • 7.3.3
    • 6.1.192
    • 6.6.162
    • 5.10.274
    • 6.12.116
    • 6.18.62
    • 5.15.225

    Vendors and products

    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 9 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Descriptionadded
      —
      In the Linux kernel, the following vulnerability has been resolved: xen-netback: defer xenvif_mcast_addr_list_free() In order for the function to legitimately avoid locking/RCU, it needs to run after all TX/RX processing has finished/stopped: Lookups happen from xenvif_start_xmit(), while adds/removes happen from xenvif_tx_action() (called out of xenvif_poll()). Move the call out of xenvif_disconnect_data() (the call to the function from connect()'s error path doesn't require any cleaning up there), and put it past the synchronization point in backend_disconnect(). This is XSA-527 / CVE-2026-100081.
      Affected versions (publisher)added
      —
      New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/100xxx/CVE-2026-100081.json">CVE-2026-100081</a>
      Referenceadded
      —
      https://git.kernel.org/stable/c/0d515c409033c8e2a645a781be3ca76ab825fc8c
      Referenceadded
      —
      https://git.kernel.org/stable/c/0e786123e46d08d2247ce93a5435e45ed9f4c5d1
      Referenceadded
      —
      https://git.kernel.org/stable/c/34f0f63dc6dc11895a17bb5672451b6b11622c99
      Referenceadded
      —
      https://git.kernel.org/stable/c/96e05a8ce243e2207704e2e7a6e7d1172730f515
      Referenceadded
      —
      https://git.kernel.org/stable/c/990d123d9eaa3ac6c979eed245658676d65ce0db
      Referenceadded
      —
      https://git.kernel.org/stable/c/a6bb2f1fa62c56279bdcdadce28d1310c5e12b62
      Referenceadded
      —
      https://git.kernel.org/stable/c/fb38fc58acb26d74fe8f7b19621fafaae3c040ff

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

    2. Record modifiedCVE Program

      Show 2 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Referenceadded
      —
      http://www.openwall.com/lists/oss-security/2026/11/06/10
      Referenceadded
      —
      http://xenbits.xen.org/xsa/advisory-527.html

      Source identifier: af854a3a-2127-422b-91ae-364da2661108

    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-2026-100081
    <a href="https://intel.neosec.eu/en/cve/CVE-2026-100081"><img src="https://intel.neosec.eu/badge/cve/CVE-2026-100081.svg?lang=en" alt="CVE-2026-100081 – NEOSEC Intel" height="20"></a>