HighCVE-2026-46086

    Linux Kernel: NULL Pointer Dereference (CVE-2026-46086)

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

    What is affected, what to do

    A flaw was found in the Linux kernel. Inconsistent handling of local Forwarding Database (FDB) entries in the bridge networking component's RCU (Read-Copy-Update) readers can lead to a null-pointer dereference.

    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 3.14..5.10.259
    • Linux Kernel lt 5.11..5.15.210
    • Linux Kernel lt 5.16..6.1.176
    • Linux Kernel lt 6.2..6.6.140
    • Linux Kernel lt 6.7..6.12.86
    • Linux Kernel lt 6.13..6.18.27
    • Linux Kernel lt 6.19..7.0.4
    Fixed in
    • Linux Kernel 5.10.259
    • Linux Kernel 5.15.210
    • Linux Kernel 6.1.176
    • Linux Kernel 6.6.140
    • Linux Kernel 6.12.86
    • Linux Kernel 6.18.27
    • Linux Kernel 7.0.4
    • Linux Kernel 7.1

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

    Metrics

    7.0

    Priority

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

    Source: Vendor (CNA), CVSS v3

    5.5

    CVSS v3

    Severity Medium on the scale from 0 to 10.

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

    0.1 %

    EPSS score

    Low — model estimates < 1% exploitation likelihood.

    Source: FIRST EPSS, percentile 2.5

    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
    45.57 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
    7.0 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
    2.5
    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
    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

    A flaw was found in the Linux kernel. Inconsistent handling of local Forwarding Database (FDB) entries in the bridge networking component's RCU (Read-Copy-Update) readers can lead to a null-pointer dereference. A local attacker could exploit this by triggering a concurrent update to an FDB entry, causing the system to crash and resulting in a Denial of Service (DoS).

    Source: suse_csaf, siemens_advisory, Debian LTS Advisories, BSI WID Portal, BSI CSAF, Ubuntu Security Notices, redhat_csaf, cvelistv5, ENISA EUVD, NVD (NIST), Microsoft Security Update Guide, 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
    • 6.19 – < 7.0.4
    • 6.2 – < 6.6.140
    • 5.11 – < 5.15.210
    • 6.13 – < 6.18.27
    • 3.14 – < 5.10.259
    • —
    • 5.16 – < 6.1.176
    • 6.7 – < 6.12.86
    • 7.0.4
    • 6.6.140
    • 5.15.210
    • 6.18.27
    • 5.10.259
    • 7.1
    • 6.1.176
    • 6.12.86
    IBMDataPower Gateway
    • < 11.0.0.3
    • < 10.6.0.11
    • < 10.5.0.23
    • 11.0.0.3
    • 10.6.0.11
    • 10.5.0.23
    IBMQRadar SIEM
    • <7.5.0 UP15 IF06
    • —
    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-gcp-5.15focal
    Linuxlinuxlinux_kernel3.14
    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 modifiedSiemens ADP

      Show 3 original changes
      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/2026/46xxx/CVE-2026-46086.json">CVE-2026-46086</a>
      Referenceadded
      —
      https://cert-portal.siemens.com/productcert/html/ssa-457936.html
      Referenceadded
      —
      https://cert-portal.siemens.com/productcert/html/ssa-784472.html

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

    2. Record modifiedLinux

      Show 24 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Referenceadded
      —
      https://git.kernel.org/stable/c/0b9e4bbfb7c949151e3acd44ed4aa33614d2e110
      Referenceadded
      —
      https://git.kernel.org/stable/c/1406c4e0ed1eaf8a29801ab1163d00fb7ee4359a
      Referenceadded
      —
      https://git.kernel.org/stable/c/5424e678f9b304e148cf5dcc047cffc7a56a3bb5
      Referenceadded
      —
      https://git.kernel.org/stable/c/81af4137a30c4c2dc694dea8cacb180bd66000ef
      Referenceadded
      —
      https://git.kernel.org/stable/c/9a2d9d4e657b23dc21f24cf139e3aeff0b61341f
      Referenceadded
      —
      https://git.kernel.org/stable/c/a6ae4511c07b91f597e461406c6330f0d4ff810e
      Referenceadded
      —
      https://git.kernel.org/stable/c/c502fa9f094cb03d1d1685c71e2105ab359bc2b8
      Referenceadded
      —
      https://git.kernel.org/stable/c/df4601653201de21b487c3e7fffd464790cab808
      Referenceremoved
      https://git.kernel.org/stable/c/0b9e4bbfb7c949151e3acd44ed4aa33614d2e110
      —
      Referenceremoved
      https://git.kernel.org/stable/c/1406c4e0ed1eaf8a29801ab1163d00fb7ee4359a
      —
      Referenceremoved
      https://git.kernel.org/stable/c/5424e678f9b304e148cf5dcc047cffc7a56a3bb5
      —
      Referenceremoved
      https://git.kernel.org/stable/c/81af4137a30c4c2dc694dea8cacb180bd66000ef
      —
      Referenceremoved
      https://git.kernel.org/stable/c/9a2d9d4e657b23dc21f24cf139e3aeff0b61341f
      —
      Referenceremoved
      https://git.kernel.org/stable/c/a6ae4511c07b91f597e461406c6330f0d4ff810e
      —
      Referenceremoved
      https://git.kernel.org/stable/c/c502fa9f094cb03d1d1685c71e2105ab359bc2b8
      —
      Referenceremoved
      https://git.kernel.org/stable/c/df4601653201de21b487c3e7fffd464790cab808
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/0b9e4bbfb7c949151e3acd44ed4aa33614d2e110 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/1406c4e0ed1eaf8a29801ab1163d00fb7ee4359a Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/5424e678f9b304e148cf5dcc047cffc7a56a3bb5 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/81af4137a30c4c2dc694dea8cacb180bd66000ef Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/9a2d9d4e657b23dc21f24cf139e3aeff0b61341f Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/a6ae4511c07b91f597e461406c6330f0d4ff810e Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/c502fa9f094cb03d1d1685c71e2105ab359bc2b8 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/df4601653201de21b487c3e7fffd464790cab808 Types: Patch
      —

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

    3. 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/2026/46xxx/CVE-2026-46086.json">CVE-2026-46086</a>
      Referenceadded
      —
      https://cert-portal.siemens.com/productcert/html/ssa-019113.html

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

    4. Initial analysis by NVDNVD

      Newly listed as affected:
      • Linux Kernel (6.7 – before 6.12.86; 6.2 – before 6.6.140; 6.13 – before 6.18.27; 6.19 – before 7.0.4; 5.16 – before 6.1.176; 5.11 – before 5.15.210; 3.14.1 – before 5.10.259; 7 individual versions)

      CVSS V3.1: AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

      Weakness type: CWE-476

      Show 11 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      CVSSadded
      —
      AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
      Weakness type (CWE)added
      —
      CWE-476
      Product configurationadded
      —
      OR *cpe:2.3:o:linux:linux_kernel:3.14:rc3:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:3.14:rc7:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:3.14:rc8:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:3.14:rc6:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:3.14:-:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:3.14:rc5:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:3.14:rc4:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.7 up to (excluding) 6.12.86 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.2 up to (excluding) 6.6.140 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.13 up to (excluding) 6.18.27 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.19 up to (excluding) 7.0.4 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.16 up to (excluding) 6.1.176 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.11 up to (excluding) 5.15.210 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 3.14.1 up to (excluding) 5.10.259
      Reference typeadded
      —
      kernel.org: https://git.kernel.org/stable/c/0b9e4bbfb7c949151e3acd44ed4aa33614d2e110 Types: Patch
      Reference typeadded
      —
      kernel.org: https://git.kernel.org/stable/c/1406c4e0ed1eaf8a29801ab1163d00fb7ee4359a Types: Patch
      Reference typeadded
      —
      kernel.org: https://git.kernel.org/stable/c/5424e678f9b304e148cf5dcc047cffc7a56a3bb5 Types: Patch
      Reference typeadded
      —
      kernel.org: https://git.kernel.org/stable/c/81af4137a30c4c2dc694dea8cacb180bd66000ef Types: Patch
      Reference typeadded
      —
      kernel.org: https://git.kernel.org/stable/c/9a2d9d4e657b23dc21f24cf139e3aeff0b61341f Types: Patch
      Reference typeadded
      —
      kernel.org: https://git.kernel.org/stable/c/a6ae4511c07b91f597e461406c6330f0d4ff810e Types: Patch
      Reference typeadded
      —
      kernel.org: https://git.kernel.org/stable/c/c502fa9f094cb03d1d1685c71e2105ab359bc2b8 Types: Patch
      Reference typeadded
      —
      kernel.org: https://git.kernel.org/stable/c/df4601653201de21b487c3e7fffd464790cab808 Types: Patch

      Source identifier: nvd@nist.gov

    5. Record modifiedLinux

      Show 4 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Referenceadded
      —
      https://git.kernel.org/stable/c/1406c4e0ed1eaf8a29801ab1163d00fb7ee4359a
      Referenceadded
      —
      https://git.kernel.org/stable/c/a6ae4511c07b91f597e461406c6330f0d4ff810e
      Referenceadded
      —
      https://git.kernel.org/stable/c/c502fa9f094cb03d1d1685c71e2105ab359bc2b8
      Affected versions (publisher)changed
      Linux, Linux
      Linux, Linux

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

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