MediumCVE-2026-45834

    Linux Kernel: NULL Pointer Dereference (CVE-2026-45834)

    Published Last modified Sources: SUSE, Debian LTS, Ubuntu, Siemens ProductCERT, BSI, CVE.org, Msrc Update Guide, EUVD

    What is affected, what to do

    In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: Fix null-ptr-deref in l2cap_sock_state_change_cb() Add the same NULL guard already present in l2cap_sock_resume_cb() and l2cap_sock_ready_cb().

    Update Linux Kernel to version 5.10.258, Linux Kernel to version 5.15.209, Linux Kernel to version 6.1.175.

    Affected
    • Linux Kernel lt 3.1..5.10.258
    • Linux Kernel lt 5.11..5.15.209
    • Linux Kernel lt 5.16..6.1.175
    • Linux Kernel lt 6.2..6.6.140
    • Linux Kernel lt 6.7..6.12.88
    • Linux Kernel lt 6.13..6.18.30
    • Linux Kernel lt 6.19..7.0.7
    Fixed in
    • Linux Kernel 5.10.258
    • Linux Kernel 5.15.209
    • Linux Kernel 6.1.175
    • Linux Kernel 6.6.140
    • Linux Kernel 6.12.88
    • Linux Kernel 6.18.30
    • Linux Kernel 7.0.7
    • Linux Kernel 7.1

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

    Metrics

    5.5

    Priority

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

    Source: NVD, CVSS v3

    5.5

    CVSS v3

    Severity Medium on the scale from 0 to 10.

    Source: SUSE, Debian LTS, Ubuntu, Siemens ProductCERT, BSI, CVE.org, Msrc Update Guide, EUVD

    0.1 %

    EPSS score

    Low — model estimates < 1% exploitation likelihood.

    Source: FIRST EPSS, percentile 2.3

    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
    45.51 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
    5.5 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
    5.5
    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
    0.1 %
    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
    2.3
    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: Bluetooth: L2CAP: Fix null-ptr-deref in l2cap_sock_state_change_cb() Add the same NULL guard already present in l2cap_sock_resume_cb() and l2cap_sock_ready_cb().

    Source: suse_csaf, Debian LTS Advisories, Ubuntu Security Notices, siemens_advisory, BSI WID Portal, BSI CSAF, cvelistv5, NVD (NIST), Microsoft Security Update Guide, ENISA EUVD, CVE.org (MITRE)

    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 – < 6.1.175
    • 6.7 – < 6.12.88
    • 6.2 – < 6.6.140
    • 6.19 – < 7.0.7
    • 5.11 – < 5.15.209
    • —
    • 3.1 – < 5.10.258
    • 6.13 – < 6.18.30
    • 6.1.175
    • 6.12.88
    • 6.6.140
    • 7.0.7
    • 5.15.209
    • 7.1
    • 5.10.258
    • 6.18.30
    Open SourceLinux Kernel
    • < 6.12.90
    • < 6.6.140
    • < 6.18.30
    • < 7.1-rc3
    • < 7.0.7
    • 6.12.90
    • 6.6.140
    • 6.18.30
    • 7.1-rc3
    • 7.0.7
    SiemensSIMATIC S7
    • 1500 TM MFP V1.1.1 GNU/Linux subsystem
    • —

    Vendors and products

    Affected operating systems

    Affected operating systems
    Linuxdebianlinuxbookworm
    Linuxdebianlinuxbullseye
    Linuxdebianlinux-6.1bullseye
    Linuxubuntulinux-oracle-7.0noble
    Linuxlinuxlinux_kernel7.1
    Linuxlinuxlinux_kernel—

    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

      Show 24 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Referenceadded
      —
      https://git.kernel.org/stable/c/0c17c8832562b2aac288e89cefd0f46074f54bcb
      Referenceadded
      —
      https://git.kernel.org/stable/c/1810e42ff6716f320c7269d5850eca48b07b7427
      Referenceadded
      —
      https://git.kernel.org/stable/c/1b1c0da227bf63479bac9982fc8d12df9aaea0fb
      Referenceadded
      —
      https://git.kernel.org/stable/c/2ff1a41a912de8517b4482e946dd951b7d80edbf
      Referenceadded
      —
      https://git.kernel.org/stable/c/5105f3e6b2df619c635b5f6a49fac131a36c7952
      Referenceadded
      —
      https://git.kernel.org/stable/c/85426e97dc72f2088ba6d27e74cd58c3fbd43e31
      Referenceadded
      —
      https://git.kernel.org/stable/c/a2dcf1a61d056aef15b63c6eae9441344d624389
      Referenceadded
      —
      https://git.kernel.org/stable/c/c88c185ae0a1067823661b220aeea613df2c127b
      Referenceremoved
      https://git.kernel.org/stable/c/0c17c8832562b2aac288e89cefd0f46074f54bcb
      —
      Referenceremoved
      https://git.kernel.org/stable/c/1810e42ff6716f320c7269d5850eca48b07b7427
      —
      Referenceremoved
      https://git.kernel.org/stable/c/1b1c0da227bf63479bac9982fc8d12df9aaea0fb
      —
      Referenceremoved
      https://git.kernel.org/stable/c/2ff1a41a912de8517b4482e946dd951b7d80edbf
      —
      Referenceremoved
      https://git.kernel.org/stable/c/5105f3e6b2df619c635b5f6a49fac131a36c7952
      —
      Referenceremoved
      https://git.kernel.org/stable/c/85426e97dc72f2088ba6d27e74cd58c3fbd43e31
      —
      Referenceremoved
      https://git.kernel.org/stable/c/a2dcf1a61d056aef15b63c6eae9441344d624389
      —
      Referenceremoved
      https://git.kernel.org/stable/c/c88c185ae0a1067823661b220aeea613df2c127b
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/0c17c8832562b2aac288e89cefd0f46074f54bcb Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/1810e42ff6716f320c7269d5850eca48b07b7427 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/1b1c0da227bf63479bac9982fc8d12df9aaea0fb Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/2ff1a41a912de8517b4482e946dd951b7d80edbf Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/5105f3e6b2df619c635b5f6a49fac131a36c7952 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/85426e97dc72f2088ba6d27e74cd58c3fbd43e31 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/a2dcf1a61d056aef15b63c6eae9441344d624389 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/c88c185ae0a1067823661b220aeea613df2c127b Types: Patch
      —

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

    2. Record modifiedSiemens ADP

      Show 2 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Affected versions (publisher)added
      —
      New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/45xxx/CVE-2026-45834.json">CVE-2026-45834</a>
      Referenceadded
      —
      https://cert-portal.siemens.com/productcert/html/ssa-784472.html

      Source identifier: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e

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