MediumCVE-2026-46165

    Linux Kernel: Improper Locking (CVE-2026-46165)

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

    What is affected, what to do

    In the Linux kernel, the following vulnerability has been resolved: openvswitch: vport: fix self-deadlock on release of tunnel ports vports are used concurrently and protected by RCU, so netdev_put() must happen after the RCU grace period. So, either in an RCU call or after the synchronize_net().

    Update Linux Kernel to version 6.1.175, Linux Kernel to version 6.6.140, Linux Kernel to version 6.12.88.

    Affected
    • Linux Kernel lt 6.1.168..6.1.175
    • Linux Kernel lt 6.6.131..6.6.140
    • Linux Kernel lt 6.12.80..6.12.88
    • Linux Kernel lt 6.18.21..6.18.30
    • Linux Kernel lt 6.19.11..6.20
    • Linux Kernel lt 7.0..7.0.7
    Fixed in
    • Linux Kernel 6.1.175
    • Linux Kernel 6.6.140
    • Linux Kernel 6.12.88
    • Linux Kernel 6.18.30
    • Linux Kernel 6.20
    • 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, EUVD, Msrc Update Guide

    0.1 %

    EPSS score

    Low — model estimates < 1% exploitation likelihood.

    Source: FIRST EPSS, percentile 0.8

    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
    45.56 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
    0.8
    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
    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-667

    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: openvswitch: vport: fix self-deadlock on release of tunnel ports vports are used concurrently and protected by RCU, so netdev_put() must happen after the RCU grace period. So, either in an RCU call or after the synchronize_net(). The rtnl_delete_link() must happen under RTNL and so can't be executed in RCU context. Calling synchronize_net() while holding RTNL is not a good idea for performance and system stability under load in general, so calling netdev_put() in RCU call is the right solution here. However, when the device is deleted, rtnl_unlock() will call netdev_run_todo() and block until all the references are gone. In the current code this means that we never reach the call_rcu() and the vport is never freed and the reference is never released, causing a self-deadlock on device removal. Fix that by moving the rcu_call() before the rtnl_unlock(), so the scheduled RCU callback will be executed when synchronize_net() is called from the rtnl_unlock()->netdev_run_todo() while the RTNL itself is already released.

    Source: suse_csaf, Debian LTS Advisories, Ubuntu Security Notices, siemens_advisory, BSI WID Portal, BSI CSAF, cvelistv5, ENISA EUVD, Microsoft Security Update Guide, NVD (NIST), 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
    • 6.6.131 – < 6.6.140
    • 6.19.11 – < 6.20
    • 6.1.168 – < 6.1.175
    • —
    • 7.0 – < 7.0.7
    • 6.18.21 – < 6.18.30
    • 6.12.80 – < 6.12.88
    • 6.6.140
    • 6.20
    • 6.1.175
    • 7.1
    • 7.0.7
    • 6.18.30
    • 6.12.88
    SiemensSIMATIC S7
    • 1500 TM MFP V1.1.1 GNU/Linux subsystem
    • —

    Vendors and products

    Affected operating systems

    Affected operating systems
    Linuxdebianlinuxbookworm
    Linuxdebianlinux-6.1bullseye
    Linuxubuntulinux-oracle-7.0noble
    Linuxlinuxlinux_kernel7.0
    Linuxlinuxlinux_kernel7.1
    Linuxlinuxlinux_kernel—

    Weakness classes (CWE)

    • CWE-667Improper Locking

      Class

      The product does not properly acquire or release a lock on a resource, leading to unexpected resource state changes and behaviors.

      Entry at MITRE CWE-667

    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 18 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Referenceadded
      —
      https://git.kernel.org/stable/c/366c482965c673565ecb8bcfb15d5548f13a6a10
      Referenceadded
      —
      https://git.kernel.org/stable/c/3df75fff46b1517eb479d8e6b8e3500763715dd0
      Referenceadded
      —
      https://git.kernel.org/stable/c/6522d59fb7de55ce0f0f285d962243ddffebb01f
      Referenceadded
      —
      https://git.kernel.org/stable/c/8ae6c15fc473c9ad03b0173330cce9a092c76154
      Referenceadded
      —
      https://git.kernel.org/stable/c/aa69918bd418e700309fdd08509dba324fb24296
      Referenceadded
      —
      https://git.kernel.org/stable/c/c741433f6c8dcdecd1d9549d89053761fd1ea413
      Referenceremoved
      https://git.kernel.org/stable/c/366c482965c673565ecb8bcfb15d5548f13a6a10
      —
      Referenceremoved
      https://git.kernel.org/stable/c/3df75fff46b1517eb479d8e6b8e3500763715dd0
      —
      Referenceremoved
      https://git.kernel.org/stable/c/6522d59fb7de55ce0f0f285d962243ddffebb01f
      —
      Referenceremoved
      https://git.kernel.org/stable/c/8ae6c15fc473c9ad03b0173330cce9a092c76154
      —
      Referenceremoved
      https://git.kernel.org/stable/c/aa69918bd418e700309fdd08509dba324fb24296
      —
      Referenceremoved
      https://git.kernel.org/stable/c/c741433f6c8dcdecd1d9549d89053761fd1ea413
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/366c482965c673565ecb8bcfb15d5548f13a6a10 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/3df75fff46b1517eb479d8e6b8e3500763715dd0 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/6522d59fb7de55ce0f0f285d962243ddffebb01f Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/8ae6c15fc473c9ad03b0173330cce9a092c76154 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/aa69918bd418e700309fdd08509dba324fb24296 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/c741433f6c8dcdecd1d9549d89053761fd1ea413 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/2026/46xxx/CVE-2026-46165.json">CVE-2026-46165</a>
      Referenceadded
      —
      https://cert-portal.siemens.com/productcert/html/ssa-784472.html

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

    3. Initial analysis by NVDNVD

      Newly listed as affected:
      • Linux Kernel (6.1.168 – before 6.1.175; 6.12.80 – before 6.12.88; 6.18.21 – before 6.18.30; 6.19.11 – before 7.0; 6.6.131 – before 6.6.140; 7.0.1 – before 7.0.7; 5 individual versions)

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

      Weakness type: CWE-667

      Show 9 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-667
      Product configurationadded
      —
      OR *cpe:2.3:o:linux:linux_kernel:7.0:rc6:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:7.0:rc7:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:7.0:-:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.1.168 up to (excluding) 6.1.175 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.12.80 up to (excluding) 6.12.88 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.18.21 up to (excluding) 6.18.30 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.19.11 up to (excluding) 7.0 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.6.131 up to (excluding) 6.6.140 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 7.0.1 up to (excluding) 7.0.7
      Reference typeadded
      —
      kernel.org: https://git.kernel.org/stable/c/366c482965c673565ecb8bcfb15d5548f13a6a10 Types: Patch
      Reference typeadded
      —
      kernel.org: https://git.kernel.org/stable/c/3df75fff46b1517eb479d8e6b8e3500763715dd0 Types: Patch
      Reference typeadded
      —
      kernel.org: https://git.kernel.org/stable/c/6522d59fb7de55ce0f0f285d962243ddffebb01f Types: Patch
      Reference typeadded
      —
      kernel.org: https://git.kernel.org/stable/c/8ae6c15fc473c9ad03b0173330cce9a092c76154 Types: Patch
      Reference typeadded
      —
      kernel.org: https://git.kernel.org/stable/c/aa69918bd418e700309fdd08509dba324fb24296 Types: Patch
      Reference typeadded
      —
      kernel.org: https://git.kernel.org/stable/c/c741433f6c8dcdecd1d9549d89053761fd1ea413 Types: Patch

      Source identifier: nvd@nist.gov

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