HighCVE-2026-53264

    Linux Kernel: Race Condition (CVE-2026-53264)

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

    What is affected, what to do

    A flaw was found in the Linux kernel's networking scheduler. A race condition, which is a problem that occurs when multiple operations try to access the same resource at the same time, exists when network filter operations are run concurrently.

    An exploit is publicly available. 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 4.14..5.10.259
    • Linux Kernel lt 5.11..5.15.210
    • Linux Kernel lt 5.16..6.1.176
    • Linux Kernel lt 6.2..6.6.143
    • Linux Kernel lt 6.7..6.12.94
    • Linux Kernel lt 6.13..6.18.36
    • Linux Kernel lt 6.19..7.0.13
    Fixed in
    • Linux Kernel 5.10.259
    • Linux Kernel 5.15.210
    • Linux Kernel 6.1.176
    • Linux Kernel 6.6.143
    • Linux Kernel 6.12.94
    • Linux Kernel 6.18.36
    • Linux Kernel 7.0.13
    • Linux Kernel 7.1

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

    Metrics

    7.8

    Priority

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

    Source: NVD, CVSS v3

    7.8

    CVSS v3

    Severity High on the scale from 0 to 10.

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

    0.5 %

    EPSS score

    Low — model estimates < 1% exploitation likelihood.

    Source: FIRST EPSS, percentile 41.7

    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
    72.38 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
    PoC (publicly reported)
    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
    7.8 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
    7.8
    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
    0.5 %
    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
    41.7
    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: proof of concept · not automatable · Technical impact: total
    Source: CISA Vulnrichment, as of 29 July 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-416

    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's networking scheduler. A race condition, which is a problem that occurs when multiple operations try to access the same resource at the same time, exists when network filter operations are run concurrently. This can lead to a Use-After-Free (UAF) vulnerability, where the system attempts to use memory that has already been released. This could potentially allow an attacker to cause system instability or execute arbitrary code.

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

    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
    • 6.7 – < 6.12.94
    • 6.13 – < 6.18.36
    • 5.11 – < 5.15.210
    • —
    • 5.16 – < 6.1.176
    • 6.19 – < 7.0.13
    • 6.2 – < 6.6.143
    • 4.14 – < 5.10.259
    • 6.12.94
    • 6.18.36
    • 5.15.210
    • 7.1
    • 6.1.176
    • 7.0.13
    • 6.6.143
    • 5.10.259
    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
    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—

    Weakness classes (CWE)

    • CWE-416Use After Free

      Variant

      The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.

      Entry at MITRE CWE-416

    Public exploit references

    Publicly reported proof-of-concepts, exploit modules and detection templates for this vulnerability. NEOSEC links to the original sources only and does not provide any exploit code.

    Public exploit references
    PoC-in-GitHub (nomi-sec)CVE-2026-53264 (opens in a new tab)github.comPoC (publicly reported)reported, not verified

    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/18af5d2ef0c4f65787fd1280c8b23286b9f2a835
      Referenceadded
      —
      https://git.kernel.org/stable/c/1f1b98fea6b9ea30507d0f2fbff6750292d097e2
      Referenceadded
      —
      https://git.kernel.org/stable/c/5057e1aca011e51ef51498c940ef96f3d3e8a305
      Referenceadded
      —
      https://git.kernel.org/stable/c/5dd51e09020c65aa53cf128e5e3517cd53b3c113
      Referenceadded
      —
      https://git.kernel.org/stable/c/8b136f18ac4b2ace5aaad3305b3f8a5d8165a009
      Referenceadded
      —
      https://git.kernel.org/stable/c/91d105d2cbe002f9c7b43a6183adedc37e1da1f7
      Referenceadded
      —
      https://git.kernel.org/stable/c/98b2e40879abf0245be5a5b7af69e0f6ff524ac3
      Referenceadded
      —
      https://git.kernel.org/stable/c/b60e9391142e983fab2be53497aa8f71fdd09cd5
      Referenceremoved
      https://git.kernel.org/stable/c/18af5d2ef0c4f65787fd1280c8b23286b9f2a835
      —
      Referenceremoved
      https://git.kernel.org/stable/c/1f1b98fea6b9ea30507d0f2fbff6750292d097e2
      —
      Referenceremoved
      https://git.kernel.org/stable/c/5057e1aca011e51ef51498c940ef96f3d3e8a305
      —
      Referenceremoved
      https://git.kernel.org/stable/c/5dd51e09020c65aa53cf128e5e3517cd53b3c113
      —
      Referenceremoved
      https://git.kernel.org/stable/c/8b136f18ac4b2ace5aaad3305b3f8a5d8165a009
      —
      Referenceremoved
      https://git.kernel.org/stable/c/91d105d2cbe002f9c7b43a6183adedc37e1da1f7
      —
      Referenceremoved
      https://git.kernel.org/stable/c/98b2e40879abf0245be5a5b7af69e0f6ff524ac3
      —
      Referenceremoved
      https://git.kernel.org/stable/c/b60e9391142e983fab2be53497aa8f71fdd09cd5
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/18af5d2ef0c4f65787fd1280c8b23286b9f2a835 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/1f1b98fea6b9ea30507d0f2fbff6750292d097e2 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/5057e1aca011e51ef51498c940ef96f3d3e8a305 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/5dd51e09020c65aa53cf128e5e3517cd53b3c113 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/8b136f18ac4b2ace5aaad3305b3f8a5d8165a009 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/91d105d2cbe002f9c7b43a6183adedc37e1da1f7 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/98b2e40879abf0245be5a5b7af69e0f6ff524ac3 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/b60e9391142e983fab2be53497aa8f71fdd09cd5 Types: Patch
      —

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

    2. Record modifiedCISA ADP

      Show 2 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Referenceadded
      —
      https://starlabs.sg/blog/2026/07-when-ai-makes-0-days-feel-like-n-days/
      Referenceremoved
      https://starlabs.sg/blog/2026/07-when-ai-makes-0-days-feel-like-n-days/
      —

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

    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/2026/53xxx/CVE-2026-53264.json">CVE-2026-53264</a>
      Referenceadded
      —
      https://cert-portal.siemens.com/productcert/html/ssa-784472.html

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

    4. Record modifiedCISA ADP

      CISA assessment (SSVC): exploitation: proof of concept, automatable: no

      Show the original change
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      SSVC assessmentadded
      —
      {"id":"CVE-2026-53264","role":"CISA Coordinator","options":[{"exploitation":"poc"},{"automatable":"no"},{"technicalImpact":"total"}],"version":"2.0.3","timestamp":"2026-07-28T00:00:00+00:00"}

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

    5. Initial analysis by NVDNVD

      Newly listed as affected:
      • Linux Kernel (5.16 – before 6.1.176; 6.2 – before 6.6.143; 5.11 – before 5.15.210; 6.13 – before 6.18.36; 6.7 – before 6.12.94; 6.19 – before 7.0.13; 4.14 – before 5.10.259; 6 individual versions)

      Weakness type: CWE-416

      Show 10 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Weakness type (CWE)added
      —
      CWE-416
      Product configurationadded
      —
      OR *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:7.1:rc3:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:* *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) 6.2 up to (excluding) 6.6.143 *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) 6.13 up to (excluding) 6.18.36 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.7 up to (excluding) 6.12.94 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.19 up to (excluding) 7.0.13 *cpe:2.3:o:linux:linux_kernel:7.1:rc5:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:7.1:rc6:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 4.14 up to (excluding) 5.10.259
      Reference typeadded
      —
      kernel.org: https://git.kernel.org/stable/c/18af5d2ef0c4f65787fd1280c8b23286b9f2a835 Types: Patch
      Reference typeadded
      —
      kernel.org: https://git.kernel.org/stable/c/1f1b98fea6b9ea30507d0f2fbff6750292d097e2 Types: Patch
      Reference typeadded
      —
      kernel.org: https://git.kernel.org/stable/c/5057e1aca011e51ef51498c940ef96f3d3e8a305 Types: Patch
      Reference typeadded
      —
      kernel.org: https://git.kernel.org/stable/c/5dd51e09020c65aa53cf128e5e3517cd53b3c113 Types: Patch
      Reference typeadded
      —
      kernel.org: https://git.kernel.org/stable/c/8b136f18ac4b2ace5aaad3305b3f8a5d8165a009 Types: Patch
      Reference typeadded
      —
      kernel.org: https://git.kernel.org/stable/c/91d105d2cbe002f9c7b43a6183adedc37e1da1f7 Types: Patch
      Reference typeadded
      —
      kernel.org: https://git.kernel.org/stable/c/98b2e40879abf0245be5a5b7af69e0f6ff524ac3 Types: Patch
      Reference typeadded
      —
      kernel.org: https://git.kernel.org/stable/c/b60e9391142e983fab2be53497aa8f71fdd09cd5 Types: Patch

      Source identifier: nvd@nist.gov

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