MediumCVE-2026-98567

    Linux Kernel: Out-of-Bounds Access (CVE-2026-98567)

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

    What is affected, what to do

    In the Linux kernel, the following vulnerability has been resolved: net: xps: reject an out of range traffic class Only the entries below dev->num_tc are valid in dev->tc_to_txq[], and dev->prio_tc_map[] may only name classes below it. netdev_set_num_tc() lowers dev->num_tc without touching either array. netdev_txq_to_tc() walks all TC_MAX_QUEUE slots and netdev_get_prio_tc_map() returns the entry as it stands, so a leftover entry is handed out as a traffic class >= dev->num_tc. Taking that class from netdev_txq_to_tc(), __netif_set_xps_queue() rejects only a negative one and indexes an XPS map sized for dev->num_tc classes: tci = j * num_tc + tc; RCU_INIT_POINTER(new_dev_maps->attr_map[tci], map); attr_map[] holds nr_ids * num_tc entries and j runs over the ids named in the mask, so a class that is not below num_tc pushes tci past the end of the map for the last ids and the store overruns it.

    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 4.10..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..6.12.112
    • Linux Kernel lt 6.13..6.18.55
    • Linux Kernel lt 6.19..7.2.9
    Fixed in
    • Linux Kernel 5.10.271
    • Linux Kernel 5.15.222
    • Linux Kernel 6.1.189
    • Linux Kernel 6.6.158
    • Linux Kernel 6.12.112
    • Linux Kernel 6.18.55
    • Linux Kernel 7.2.9
    • Linux Kernel 7.3

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

    Metrics

    6.7

    Priority

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

    Source: Vendor (CNA), CVSS v3

    6.7

    CVSS v3

    Severity Medium on the scale from 0 to 10.

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

    0.2 %

    EPSS score

    Low — model estimates < 1% exploitation likelihood.

    Source: FIRST EPSS, percentile 12.1

    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
    64.68 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
    6.7 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
    6.7
    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
    12.1
    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: net: xps: reject an out of range traffic class Only the entries below dev->num_tc are valid in dev->tc_to_txq[], and dev->prio_tc_map[] may only name classes below it. netdev_set_num_tc() lowers dev->num_tc without touching either array. netdev_txq_to_tc() walks all TC_MAX_QUEUE slots and netdev_get_prio_tc_map() returns the entry as it stands, so a leftover entry is handed out as a traffic class >= dev->num_tc. Taking that class from netdev_txq_to_tc(), __netif_set_xps_queue() rejects only a negative one and indexes an XPS map sized for dev->num_tc classes: tci = j * num_tc + tc; RCU_INIT_POINTER(new_dev_maps->attr_map[tci], map); attr_map[] holds nr_ids * num_tc entries and j runs over the ids named in the mask, so a class that is not below num_tc pushes tci past the end of the map for the last ids and the store overruns it. Any caller that lowers num_tc leaves such entries behind, and mqprio_destroy() tears down with netdev_set_num_tc(dev, 0) rather than netdev_reset_tc(). After mqprio with 8 classes then 1, tc_to_txq[1..7] still describe txq 1..7. The splat is from an XPS write to txq 2 on a veth with 8 rx queues: attr_map[] has 8 * 1 entries, tci = j + 2, and j == 6 stores one past the end of the 88-byte map: BUG: KASAN: slab-out-of-bounds in __netif_set_xps_queue (net/core/dev.c:2954) Write of size 8 at addr ffff88813016bc58 by task xps_oob/634 __netif_set_xps_queue (net/core/dev.c:2954) xps_rxqs_store (net/core/net-sysfs.c:1880) netdev_queue_attr_store (net/core/net-sysfs.c:1390) Allocated by task 634: __kmalloc_noprof (mm/slub.c:5439) __netif_set_xps_queue (net/core/dev.c:2937) The buggy address is located 0 bytes to the right of allocated 88-byte region [ffff88813016bc00, ffff88813016bc58) Reject a class the map has no room for.

    Source: Debian LTS Advisories, cvelistv5, NVD (NIST), 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
    • 5.16 – < 6.1.189
    • 4.10 – < 5.10.271
    • 6.13 – < 6.18.55
    • 6.2 – < 6.6.158
    • —
    • 6.7 – < 6.12.112
    • 5.11 – < 5.15.222
    • 6.19 – < 7.2.9
    • 6.1.189
    • 5.10.271
    • 6.18.55
    • 6.6.158
    • 7.3
    • 6.12.112
    • 5.15.222
    • 7.2.9

    Vendors and products

    Affected operating systems

    Affected operating systems
    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. 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/2026/98xxx/CVE-2026-98567.json">CVE-2026-98567</a>

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

    2. 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: net: xps: reject an out of range traffic class Only the entries below dev->num_tc are valid in dev->tc_to_txq[], and dev->prio_tc_map[] may only name classes below it. netdev_set_num_tc() lowers dev->num_tc without touching either array. netdev_txq_to_tc() walks all TC_MAX_QUEUE slots and netdev_get_prio_tc_map() returns the entry as it stands, so a leftover entry is handed out as a traffic class >= dev->num_tc. Taking that class from netdev_txq_to_tc(), __netif_set_xps_queue() rejects only a negative one and indexes an XPS map sized for dev->num_tc classes: tci = j * num_tc + tc; RCU_INIT_POINTER(new_dev_maps->attr_map[tci], map); attr_map[] holds nr_ids * num_tc entries and j runs over the ids named in the mask, so a class that is not below num_tc pushes tci past the end of the map for the last ids and the store overruns it. Any caller that lowers num_tc leaves such entries behind, and mqprio_destroy() tears down with netdev_set_num_tc(dev, 0) rather than netdev_reset_tc(). After mqprio with 8 classes then 1, tc_to_txq[1..7] still describe txq 1..7. The splat is from an XPS write to txq 2 on a veth with 8 rx queues: attr_map[] has 8 * 1 entries, tci = j + 2, and j == 6 stores one past the end of the 88-byte map: BUG: KASAN: slab-out-of-bounds in __netif_set_xps_queue (net/core/dev.c:2954) Write of size 8 at addr ffff88813016bc58 by task xps_oob/634 __netif_set_xps_queue (net/core/dev.c:2954) xps_rxqs_store (net/core/net-sysfs.c:1880) netdev_queue_attr_store (net/core/net-sysfs.c:1390) Allocated by task 634: __kmalloc_noprof (mm/slub.c:5439) __netif_set_xps_queue (net/core/dev.c:2937) The buggy address is located 0 bytes to the right of allocated 88-byte region [ffff88813016bc00, ffff88813016bc58) Reject a class the map has no room for.
      Affected versions (publisher)added
      —
      New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/98xxx/CVE-2026-98567.json">CVE-2026-98567</a>
      Referenceadded
      —
      https://git.kernel.org/stable/c/1cb8e40525a72c9f1e1cf94c68c172b3b9bbdc81
      Referenceadded
      —
      https://git.kernel.org/stable/c/2cc1c3977acbffc417fb5b57699d1df3dcffb5fd
      Referenceadded
      —
      https://git.kernel.org/stable/c/4da3b7b8b50f3e2fde54a4c18a82a8e3f6223910
      Referenceadded
      —
      https://git.kernel.org/stable/c/6ea8f643053f33622f9116e4e1db58306ece45e3
      Referenceadded
      —
      https://git.kernel.org/stable/c/930318290d8509e864c015fe6c9239470b3c579c
      Referenceadded
      —
      https://git.kernel.org/stable/c/967e10f40a0c6732db299cbe001df0e859196055
      Referenceadded
      —
      https://git.kernel.org/stable/c/9e841723ba482d41ecbf90241c756a16cdfea949
      Referenceadded
      —
      https://git.kernel.org/stable/c/eff227a3cb4d0089fbb85c73480bf8abf2e5ae7f

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

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