MediumCVE-2026-98891

    Linux Kernel: security vulnerability (CVE-2026-98891)

    Published Last modified Sources: BSI, Msrc Update Guide, CVE.org

    What is affected, what to do

    In the Linux kernel, the following vulnerability has been resolved: wifi: mac80211: validate deauth frame length before reason access ieee80211_rx_mgmt_deauth() reads the deauth reason code before checking that the fixed field is actually present in the received frame. Validate the deauth frame length first and only then read the reason code.

    Update Linux Kernel to version 5.10.271, Linux Kernel to version 5.15.222, Linux Kernel to version 6.1.189.

    Affected
    • Linux Kernel lt 4.2..5.10.271
    • Linux Kernel lt 5.11..5.15.222
    • Linux Kernel lt 5.16..6.1.189
    • Linux Kernel lt 6.2..6.6.158
    • Linux Kernel lt 6.7..6.12.111
    • Linux Kernel lt 6.13..6.18.53
    • Linux Kernel lt 6.19..7.2
    Fixed in
    • Linux Kernel 5.10.271
    • Linux Kernel 5.15.222
    • Linux Kernel 6.1.189
    • Linux Kernel 6.6.158
    • Linux Kernel 6.12.111
    • Linux Kernel 6.18.53
    • Linux Kernel 7.2

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

    Metrics

    4.3

    Priority

    XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.

    Source: Vendor (CNA), CVSS v3

    4.3

    CVSS v3

    Severity Medium on the scale from 0 to 10.

    Source: BSI, Msrc Update Guide, CVE.org

    0.2 %

    EPSS score

    Low — model estimates < 1% exploitation likelihood.

    Source: FIRST EPSS, percentile 7.4

    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
    51.94 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
    4.3 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
    4.3
    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: wifi: mac80211: validate deauth frame length before reason access ieee80211_rx_mgmt_deauth() reads the deauth reason code before checking that the fixed field is actually present in the received frame. Validate the deauth frame length first and only then read the reason code.

    Source: BSI CSAF, BSI WID Portal, Microsoft Security Update Guide, 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 – < 7.2
    • 5.16 – < 6.1.189
    • 6.13 – < 6.18.53
    • 6.2 – < 6.6.158
    • 4.2 – < 5.10.271
    • 6.7 – < 6.12.111
    • 5.11 – < 5.15.222
    • 7.2
    • 6.1.189
    • 6.18.53
    • 6.6.158
    • 5.10.271
    • 6.12.111
    • 5.15.222

    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: wifi: mac80211: validate deauth frame length before reason access ieee80211_rx_mgmt_deauth() reads the deauth reason code before checking that the fixed field is actually present in the received frame. Validate the deauth frame length first and only then read the reason code.
      Affected versions (publisher)added
      —
      New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/98xxx/CVE-2026-98891.json">CVE-2026-98891</a>
      Referenceadded
      —
      https://git.kernel.org/stable/c/4a360c6e18dfa9d70006c7247a6a8cc8dfe0d60f
      Referenceadded
      —
      https://git.kernel.org/stable/c/51092dc769f021e9634474e1bd5a561da477fbdb
      Referenceadded
      —
      https://git.kernel.org/stable/c/7a5ef1fd654d0e90d59aa32c881789c8bcc4125a
      Referenceadded
      —
      https://git.kernel.org/stable/c/80d1a110e9096b5bf41497f6b151154084862385
      Referenceadded
      —
      https://git.kernel.org/stable/c/9df64ad43e1f2c036667bba2bf385e9d7b3af564
      Referenceadded
      —
      https://git.kernel.org/stable/c/a6ed4c00ccdc15011a73daa2b38af9fc5a2c543e
      Referenceadded
      —
      https://git.kernel.org/stable/c/a78689e2beed200d4590318612c74ae25c9408cf

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

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