CriticalCVE-2026-53228

    Linux Kernel: Denial of Service (CVE-2026-53228)

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

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    What is affected, what to do

    A flaw was found in the Linux kernel's Simple Internet Transition (SIT) tunnel driver for IPv6. When processing network traffic with Generic Segmentation Offload (GSO) enabled, the driver may use a stale pointer to the inner IPv6 header after the socket buffer (skb) head has been reallocated.

    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 3.18..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

    9.8

    Priority

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

    Source: Vendor (CNA), CVSS v3

    9.8

    CVSS v3

    Severity Critical on the scale from 0 to 10.

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

    0.6 %

    EPSS score

    Low — model estimates < 1% exploitation likelihood.

    Source: FIRST EPSS, percentile 47.6

    Show all metrics
    Severity
    Critical
    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
    86.28 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
    9.8 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
    9.8
    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
    47.6
    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 · 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-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 Simple Internet Transition (SIT) tunnel driver for IPv6. When processing network traffic with Generic Segmentation Offload (GSO) enabled, the driver may use a stale pointer to the inner IPv6 header after the socket buffer (skb) head has been reallocated. This can lead to reading from freed memory, potentially allowing an attacker to cause a denial of service or gain access to sensitive information.

    Source: suse_csaf, Debian LTS Advisories, HKCERT (CC BY 3.0 HK) · HKCERT rating: medium, BSI WID Portal, BSI CSAF, siemens_advisory, Ubuntu Security Notices, redhat_csaf, NVD (NIST), Microsoft Security Update Guide, CVE.org (MITRE), cvelistv5

    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
    • 3.18 – < 5.10.259
    • —
    • 5.16 – < 6.1.176
    • 6.19 – < 7.0.13
    • 6.2 – < 6.6.143
    • 6.12.94
    • 6.18.36
    • 5.15.210
    • 5.10.259
    • 7.1
    • 6.1.176
    • 7.0.13
    • 6.6.143
    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
    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

    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-416

      Show the original change
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Weakness type (CWE)added
      —
      CWE-416

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

    2. Record modifiedCISA ADP

      CISA assessment (SSVC): exploitation: none known, automatable: yes

      Show the original change
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      SSVC assessmentadded
      —
      {"id":"CVE-2026-53228","role":"CISA Coordinator","options":[{"exploitation":"none"},{"automatable":"yes"},{"technicalImpact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T15:27:17.714387Z"}

      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-2026-53228.json">CVE-2026-53228</a>
      Referenceadded
      —
      https://cert-portal.siemens.com/productcert/html/ssa-784472.html

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

    4. Record modifiedLinux

      Show 24 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Referenceadded
      —
      https://git.kernel.org/stable/c/0bfa7bba1f41aaf5f0604dc712bb4701493e3aa0
      Referenceadded
      —
      https://git.kernel.org/stable/c/1132e5edc2866c3530be17622153a597095f0e43
      Referenceadded
      —
      https://git.kernel.org/stable/c/2fa49b2715e1bad12ce3b0fa64e234d9582c8193
      Referenceadded
      —
      https://git.kernel.org/stable/c/59f80c919713250fe5d25a4d9aea4e49580fa1d4
      Referenceadded
      —
      https://git.kernel.org/stable/c/9c67b44edb3598d234efae6e44649eb993c03da5
      Referenceadded
      —
      https://git.kernel.org/stable/c/cb658c2f5f7977c2a1c77c9f239f4bc8196edb5c
      Referenceadded
      —
      https://git.kernel.org/stable/c/f0e42f0c4337b1f220de1ddd63f47197c7dee4de
      Referenceadded
      —
      https://git.kernel.org/stable/c/fddd41445a0537b093e6b3f6232c9933cad1e48b
      Referenceremoved
      https://git.kernel.org/stable/c/0bfa7bba1f41aaf5f0604dc712bb4701493e3aa0
      —
      Referenceremoved
      https://git.kernel.org/stable/c/1132e5edc2866c3530be17622153a597095f0e43
      —
      Referenceremoved
      https://git.kernel.org/stable/c/2fa49b2715e1bad12ce3b0fa64e234d9582c8193
      —
      Referenceremoved
      https://git.kernel.org/stable/c/59f80c919713250fe5d25a4d9aea4e49580fa1d4
      —
      Referenceremoved
      https://git.kernel.org/stable/c/9c67b44edb3598d234efae6e44649eb993c03da5
      —
      Referenceremoved
      https://git.kernel.org/stable/c/cb658c2f5f7977c2a1c77c9f239f4bc8196edb5c
      —
      Referenceremoved
      https://git.kernel.org/stable/c/f0e42f0c4337b1f220de1ddd63f47197c7dee4de
      —
      Referenceremoved
      https://git.kernel.org/stable/c/fddd41445a0537b093e6b3f6232c9933cad1e48b
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/0bfa7bba1f41aaf5f0604dc712bb4701493e3aa0 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/1132e5edc2866c3530be17622153a597095f0e43 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/2fa49b2715e1bad12ce3b0fa64e234d9582c8193 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/59f80c919713250fe5d25a4d9aea4e49580fa1d4 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/9c67b44edb3598d234efae6e44649eb993c03da5 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/cb658c2f5f7977c2a1c77c9f239f4bc8196edb5c Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/f0e42f0c4337b1f220de1ddd63f47197c7dee4de Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/fddd41445a0537b093e6b3f6232c9933cad1e48b Types: Patch
      —

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

    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; 3.18 – before 5.10.259; 7 individual versions)
      Show 10 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Weakness type (CWE)added
      —
      NVD-CWE-noinfo
      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:7.1:rc7:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 3.18 up to (excluding) 5.10.259
      Reference typeadded
      —
      kernel.org: https://git.kernel.org/stable/c/0bfa7bba1f41aaf5f0604dc712bb4701493e3aa0 Types: Patch
      Reference typeadded
      —
      kernel.org: https://git.kernel.org/stable/c/1132e5edc2866c3530be17622153a597095f0e43 Types: Patch
      Reference typeadded
      —
      kernel.org: https://git.kernel.org/stable/c/2fa49b2715e1bad12ce3b0fa64e234d9582c8193 Types: Patch
      Reference typeadded
      —
      kernel.org: https://git.kernel.org/stable/c/59f80c919713250fe5d25a4d9aea4e49580fa1d4 Types: Patch
      Reference typeadded
      —
      kernel.org: https://git.kernel.org/stable/c/9c67b44edb3598d234efae6e44649eb993c03da5 Types: Patch
      Reference typeadded
      —
      kernel.org: https://git.kernel.org/stable/c/cb658c2f5f7977c2a1c77c9f239f4bc8196edb5c Types: Patch
      Reference typeadded
      —
      kernel.org: https://git.kernel.org/stable/c/f0e42f0c4337b1f220de1ddd63f47197c7dee4de Types: Patch
      Reference typeadded
      —
      kernel.org: https://git.kernel.org/stable/c/fddd41445a0537b093e6b3f6232c9933cad1e48b Types: Patch

      Source identifier: nvd@nist.gov

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