HighCVE-2026-63976

    Linux Kernel: Use of Multiple Resources with Duplicate Identifier (CVE-2026-63976)

    Published Last modified Sources: SUSE, Ubuntu, CVE.org, BSI

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    What is affected, what to do

    In the Linux kernel, the following vulnerability has been resolved: Bluetooth: l2cap: clear chan->ident on ECRED reconfiguration success l2cap_ecred_reconf_rsp() returns early on success without clearing chan->ident. Every other L2CAP response handler (l2cap_ecred_conn_rsp, l2cap_le_connect_rsp, l2cap_config_rsp) clears chan->ident after a successful transaction to prevent the channel from matching subsequent responses with the recycled ident value.

    Update Linux Kernel to version 5.10.259, Linux Kernel to version 5.15.210, Linux Kernel to version 6.1.176.

    Affected
    • Linux Kernel lt 5.7..5.10.259
    • Linux Kernel lt 5.11..5.15.210
    • Linux Kernel lt 5.16..6.1.176
    • Linux Kernel lt 6.2..6.6.143
    • Linux Kernel lt 6.7..6.12.93
    • Linux Kernel lt 6.13..6.18.35
    • Linux Kernel lt 6.19..7.0.12
    Fixed in
    • Linux Kernel 5.10.259
    • Linux Kernel 5.15.210
    • Linux Kernel 6.1.176
    • Linux Kernel 6.6.143
    • Linux Kernel 6.12.93
    • Linux Kernel 6.18.35
    • Linux Kernel 7.0.12
    • Linux Kernel 7.1

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

    Metrics

    8.8

    Priority

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

    Source: NVD, CVSS v3

    8.8

    CVSS v3

    Severity High on the scale from 0 to 10.

    Source: SUSE, Ubuntu, CVE.org, BSI

    0.6 %

    EPSS score

    Low — model estimates < 1% exploitation likelihood.

    Source: FIRST EPSS, percentile 47.1

    Show all metrics
    Severity
    High
    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
    82.45 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
    8.8 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
    8.8
    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
    0.6 %
    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
    47.1
    High — this CVE ranks above the median of all CVEs scored today (rank ≥ 36%).
    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
    CISA assessment (SSVC)
    Exploitation: none known · not automatable · Technical impact: total
    Source: CISA Vulnrichment, as of 16 October 2026
    CWE

    CWE is a catalogue of typical weakness types in software and hardware — such as flawed input validation, unsafe memory handling or poor authentication. Where a CVE names a concrete vulnerability in a concrete product, a CWE describes the underlying class of defect.

    Read in glossary
    CWE-694

    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
    High technical severity: assess and remediate the vulnerability in vulnerability handling under Art. 21(2)(e) NIS2 and document the decision.
    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: Bluetooth: l2cap: clear chan->ident on ECRED reconfiguration success l2cap_ecred_reconf_rsp() returns early on success without clearing chan->ident. Every other L2CAP response handler (l2cap_ecred_conn_rsp, l2cap_le_connect_rsp, l2cap_config_rsp) clears chan->ident after a successful transaction to prevent the channel from matching subsequent responses with the recycled ident value. A remote attacker that completed a reconfiguration as the peer can replay a failure response with the stale ident, causing the kernel to match and destroy the already-established channel via l2cap_chan_del(chan, ECONNRESET). Clear chan->ident for all matching channels on success, and harden the failure path by using l2cap_chan_hold_unless_zero() consistent with other L2CAP handlers (l2cap_le_command_rej, __l2cap_get_chan_by_ident).

    Source: suse_csaf, Ubuntu Security Notices, cvelistv5, NVD (NIST), 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
    • 6.13 – < 6.18.35
    • 6.7 – < 6.12.93
    • 5.11 – < 5.15.210
    • 6.19 – < 7.0.12
    • 5.7 – < 5.10.259
    • —
    • 5.16 – < 6.1.176
    • 6.2 – < 6.6.143
    • 6.18.35
    • 6.12.93
    • 5.15.210
    • 7.0.12
    • 5.10.259
    • 7.1
    • 6.1.176
    • 6.6.143

    Vendors and products

    Affected operating systems

    Affected operating systems
    Linuxubuntulinuxnoble
    Linuxubuntulinux-awsnoble
    Linuxubuntulinux-aws-6.8jammy
    Linuxubuntulinux-aws-fipsnoble
    Linuxubuntulinux-azurenoble
    Linuxubuntulinux-azure-6.8jammy
    Linuxubuntulinux-azure-fdenoble
    Linuxubuntulinux-azure-fde-6.8jammy
    Linuxubuntulinux-azure-fipsnoble
    Linuxubuntulinux-fipsnoble
    Linuxubuntulinux-gcpnoble
    Linuxubuntulinux-gcp-6.8jammy
    Linuxubuntulinux-gcp-fipsnoble
    Linuxubuntulinux-gkenoble
    Linuxubuntulinux-gkeopnoble
    Linuxubuntulinux-ibmnoble
    Linuxubuntulinux-ibm-6.8jammy
    Linuxubuntulinux-lowlatencynoble
    Linuxubuntulinux-lowlatency-hwe-6.8jammy
    Linuxubuntulinux-nvidiajammy
    Linuxubuntulinux-nvidianoble
    Linuxubuntulinux-nvidia-6.8jammy
    Linuxubuntulinux-nvidia-lowlatencynoble
    Linuxubuntulinux-nvidia-tegrajammy

    Weakness classes (CWE)

    • CWE-694Use of Multiple Resources with Duplicate Identifier

      Base

      The product uses multiple resources that can have the same identifier, in a context in which unique identifiers are required.

      Entry at MITRE CWE-694

    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 modifiedCISA ADP

      Weakness type: CWE-694

      Show the original change
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Weakness type (CWE)added
      —
      CWE-694

      Source identifier: 134c704f-9b21-4f2e-91b3-4a467353bcc0

    2. Record modifiedLinux

      Show 16 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Referenceadded
      —
      https://git.kernel.org/stable/c/00e1950716c6ed67d74777b2db286b0fa23b4be9
      Referenceadded
      —
      https://git.kernel.org/stable/c/3b5b5f423b4fd23404a393bda8adba3cd6f74ef1
      Referenceadded
      —
      https://git.kernel.org/stable/c/59f5ecf6ad5c4db6ae81965a96156954a3b0d89a
      Referenceadded
      —
      https://git.kernel.org/stable/c/8e7977afaef37c6bd2b2654f1bce6ab40d471147
      Referenceadded
      —
      https://git.kernel.org/stable/c/ae0152d77d101c920769934fb102b18de0c6f526
      Referenceadded
      —
      https://git.kernel.org/stable/c/c2afd2613fda90107c5e2fe8e855627451749c78
      Referenceadded
      —
      https://git.kernel.org/stable/c/cc2b4f749de09975bfa06e58bbbad2f6acd4c79c
      Referenceadded
      —
      https://git.kernel.org/stable/c/f39049304ba655ffcbb92edbdf8c51a1f1210bed
      Referenceremoved
      https://git.kernel.org/stable/c/00e1950716c6ed67d74777b2db286b0fa23b4be9
      —
      Referenceremoved
      https://git.kernel.org/stable/c/3b5b5f423b4fd23404a393bda8adba3cd6f74ef1
      —
      Referenceremoved
      https://git.kernel.org/stable/c/59f5ecf6ad5c4db6ae81965a96156954a3b0d89a
      —
      Referenceremoved
      https://git.kernel.org/stable/c/8e7977afaef37c6bd2b2654f1bce6ab40d471147
      —
      Referenceremoved
      https://git.kernel.org/stable/c/ae0152d77d101c920769934fb102b18de0c6f526
      —
      Referenceremoved
      https://git.kernel.org/stable/c/c2afd2613fda90107c5e2fe8e855627451749c78
      —
      Referenceremoved
      https://git.kernel.org/stable/c/cc2b4f749de09975bfa06e58bbbad2f6acd4c79c
      —
      Referenceremoved
      https://git.kernel.org/stable/c/f39049304ba655ffcbb92edbdf8c51a1f1210bed
      —

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

    3. Record modifiedCISA ADP

      CISA assessment (SSVC): exploitation: none known, automatable: no

      Show the original change
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      SSVC assessmentadded
      —
      {"id":"CVE-2026-63976","role":"CISA Coordinator","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T15:34:26.280157Z"}

      Source identifier: 134c704f-9b21-4f2e-91b3-4a467353bcc0

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