MediumCVE-2026-100080

    Linux Kernel: Mehrere Schwachstellen

    Published Sources: BSI

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    What is affected, what to do

    In the Linux kernel, the following vulnerability has been resolved: xen-netback: Fix UAF when reading statistics data The network statistic data in the driver is protected by RCU. Unfortunately when tearing down the queues after an error during connecting to the frontend (e.g. due to illegal Xenstore data filled in by the guest), the statistic data is being freed without synchronizing the RCU state.

    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 *..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

    5.6

    XIEM Effective CVSS

    Highest available CVSS rating from NVD and vendor data.

    Source: Vendor (CNA), CVSS v3

    5.6

    CVSS v3

    Severity Medium on the scale from 0 to 10.

    Source: BSI

    0.3 %

    EPSS score

    Low — model estimates < 1% exploitation likelihood.

    Source: FIRST EPSS, percentile 19.0

    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
    57.69 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
    5.6 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
    5.6
    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
    0.3 %
    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
    19.0
    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: Fix UAF when reading statistics data The network statistic data in the driver is protected by RCU. Unfortunately when tearing down the queues after an error during connecting to the frontend (e.g. due to illegal Xenstore data filled in by the guest), the statistic data is being freed without synchronizing the RCU state. In case the data is being read via sysfs in this phase, access to already freed memory or memory being in new use is possible. Fix that by calling synchronize_net() before freeing the queue data. This is XSA-526 / CVE-2026-100080

    Source: BSI WID Portal

    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
    • 2.6.18 – < 6.12.117
    • 2.6.33 – < 6.12.117
    • 3.14 – < 6.12.117
    • 3.6 – < 7.3.2
    • 3.7 – < 7.3.2
    • 4.0 – < 6.12.117
    • 4.11 – < 5.10.274
    • 5.11 – < 5.15.225
    • 5.16 – < 6.1.192
    • 5.2 – < 6.12.117
    • 6.13 – < 6.18.61
    • 6.13 – < 6.18.62
    • 6.19 – < 7.2.15
    • 6.19 – < 7.3
    • 6.19 – < 7.3.2
    • 6.19 – < 7.3.3
    • 6.2 – < 6.6.162
    • 6.7 – < 6.12.116
    • 7.2.8 – < 7.3
    • 7.3 – < 7.3.2
    • 7.4 – < 7.4-rc1
    • < 5.10.274
    • < 6.12.117
    • 6.12.117
    • 6.12.117
    • 6.12.117
    • 7.3.2
    • 7.3.2
    • 6.12.117
    • 5.10.274
    • 5.15.225
    • 6.1.192
    • 6.12.117
    • 6.18.61
    • 6.18.62
    • 7.2.15
    • 7.3
    • 7.3.2
    • 7.3.3
    • 6.6.162
    • 6.12.116
    • 7.3
    • 7.3.2
    • 7.4-rc1
    • 5.10.274
    • 6.12.117
    From bundled advisories, not CVE-specific (2)

    Product list of a bundled advisory that does not state which product this CVE affects.

    Products from bundled advisories
    Affected versionsFixed in
    linuxlinux
    • ksmbd RCEs only matter if the in-kernel SMB server (ksmbd) is loaded and serving shares; SMB Direct bug needs an RDMA device and
    • Reports were tested on Linux 7.3-rc1 and 7.3-rc3 (Debian trixie); exact first affected versions not published
    • —
    • —

    Vendors and products

    Affected operating systems

    Affected operating systems
    Linuxdebianlinuxtrixie
    Linuxdebianlinux-6.12bookworm

    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: Fix UAF when reading statistics data The network statistic data in the driver is protected by RCU. Unfortunately when tearing down the queues after an error during connecting to the frontend (e.g. due to illegal Xenstore data filled in by the guest), the statistic data is being freed without synchronizing the RCU state. In case the data is being read via sysfs in this phase, access to already freed memory or memory being in new use is possible. Fix that by calling synchronize_net() before freeing the queue data. This is XSA-526 / CVE-2026-100080
      Affected versions (publisher)added
      —
      New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/100xxx/CVE-2026-100080.json">CVE-2026-100080</a>
      Referenceadded
      —
      https://git.kernel.org/stable/c/36f858f228e3f955b9336af7f94634747c221518
      Referenceadded
      —
      https://git.kernel.org/stable/c/37d5a73170579b30e67cc8b19ec69715eea3a6b6
      Referenceadded
      —
      https://git.kernel.org/stable/c/4223b33be49ee09acb6f1d26beb4a36dd3b8d63a
      Referenceadded
      —
      https://git.kernel.org/stable/c/4867687b6ad28ab84bc0811d8f8f9972e769da02
      Referenceadded
      —
      https://git.kernel.org/stable/c/6cd611d2abdd8623a554e14145f82c1cb4e4467a
      Referenceadded
      —
      https://git.kernel.org/stable/c/89e534265b62c94749639350200b10370564bb3a
      Referenceadded
      —
      https://git.kernel.org/stable/c/ab9cdf1291be551da999510b30216a2886074d7a

      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/2026/11/06/9
      Referenceadded
      —
      http://xenbits.xen.org/xsa/advisory-526.html

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

    Linked CVEs

    Linked CVEs
    MediumCVE-2026-99284Linux Kernel: Privilege Escalation4.7—
    LowCVE-2026-99283Linux Kernel: security vulnerability3.7—
    MediumCVE-2026-99282Linux Kernel: Use-After-Free4.1—
    HighCVE-2026-99281Linux Kernel: security vulnerability7.1—
    Not ratedCVE-2026-99280Linux Kernel: security vulnerability0.0—
    Not ratedCVE-2026-99279Linux Kernel: security vulnerability0.0—
    Not ratedCVE-2026-99278Linux Kernel: security vulnerability0.0—
    HighCVE-2026-99277Linux Kernel: security vulnerability7.5—
    Not ratedCVE-2026-99276Linux Kernel: security vulnerability0.0—
    MediumCVE-2026-99275Linux Kernel: security vulnerability6.5—
    MediumCVE-2026-99274Linux Kernel: security vulnerability6.5—
    MediumCVE-2026-99273Linux Kernel: security vulnerability6.5—
    MediumCVE-2026-99272Linux Kernel: Out-of-Bounds Access6.5—
    MediumCVE-2026-99271Linux Kernel: Use-After-Free5.5—
    MediumCVE-2026-100082Linux Kernel: security vulnerability4.7—
    MediumCVE-2026-100081Linux Kernel: security vulnerability6.0—
    MediumCVE-2026-100080Linux Kernel: security vulnerability5.6—
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