CriticalCVE-2026-53384

    Linux Kernel: Use-After-Free (CVE-2026-53384)

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

    What is affected, what to do

    In the Linux kernel, the following vulnerability has been resolved: serial: 8250_dw: unregister 8250 port if clk_notifier_register() fails dw8250_probe() registers the 8250 port via serial8250_register_8250_port() and then, if the device has a clock, registers a clock notifier. If clk_notifier_register() fails, probe returns the error but leaves the 8250 port registered.

    Update Linux Kernel to version 6.1.177, Linux Kernel to version 6.6.144, Linux Kernel to version 6.12.95.

    Affected
    • Linux Kernel lt 5.19..6.1.177
    • Linux Kernel lt 6.2..6.6.144
    • Linux Kernel lt 6.7..6.12.95
    • Linux Kernel lt 6.13..6.18.38
    • Linux Kernel lt 6.19..7.0.14
    • Linux Kernel lt 7.1..7.1.2
    Fixed in
    • Linux Kernel 6.1.177
    • Linux Kernel 6.6.144
    • Linux Kernel 6.12.95
    • Linux Kernel 6.18.38
    • Linux Kernel 7.0.14
    • Linux Kernel 7.1.2
    • Linux Kernel 7.2

    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: NVD, CVSS v3

    9.8

    CVSS v3

    Severity Critical on the scale from 0 to 10.

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

    0.5 %

    EPSS score

    Low — model estimates < 1% exploitation likelihood.

    Source: FIRST EPSS, percentile 43.8

    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
    85.37 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
    0.5 %
    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
    43.8
    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

    In the Linux kernel, the following vulnerability has been resolved: serial: 8250_dw: unregister 8250 port if clk_notifier_register() fails dw8250_probe() registers the 8250 port via serial8250_register_8250_port() and then, if the device has a clock, registers a clock notifier. If clk_notifier_register() fails, probe returns the error but leaves the 8250 port registered. The matching serial8250_unregister_port() lives in dw8250_remove(), which is not called when probe fails, so the port slot stays occupied until the device is rebound or the system is rebooted. The devm-allocated driver data is freed while the port still references it (via the saved private_data and serial_in/serial_out callbacks), so any access to that port slot before a rebind is a use-after-free hazard. Unregister the port on the clk_notifier_register() error path.

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

    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
    • 7.1 – < 7.1.2
    • 5.19 – < 6.1.177
    • 6.7 – < 6.12.95
    • 6.2 – < 6.6.144
    • 6.13 – < 6.18.38
    • —
    • 6.19 – < 7.0.14
    • 7.1.2
    • 6.1.177
    • 6.12.95
    • 6.6.144
    • 6.18.38
    • 7.2
    • 7.0.14

    Vendors and products

    Affected operating systems

    Affected operating systems
    Linuxdebianlinux-6.1bullseye
    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 modifiedLinux

      Show 21 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Referenceadded
      —
      https://git.kernel.org/stable/c/07ffe414a708ae60551401cec5d727ed156b8caf
      Referenceadded
      —
      https://git.kernel.org/stable/c/10fc708b4de7f86002d2d735a2dbf3b5b7f65692
      Referenceadded
      —
      https://git.kernel.org/stable/c/3d205fe80f2181f0109150ad1fa06ee5bc046935
      Referenceadded
      —
      https://git.kernel.org/stable/c/511d2b92f8d20de04acafab676150d26fb5c67f4
      Referenceadded
      —
      https://git.kernel.org/stable/c/778b9dda4b24005a27bcd9c35c110bf8d7f259ca
      Referenceadded
      —
      https://git.kernel.org/stable/c/ccdf4510a3873b14e5e348cdb038717996f09fda
      Referenceadded
      —
      https://git.kernel.org/stable/c/d72650a4f334581b23a1892b888a4cb1be142f76
      Referenceremoved
      https://git.kernel.org/stable/c/07ffe414a708ae60551401cec5d727ed156b8caf
      —
      Referenceremoved
      https://git.kernel.org/stable/c/10fc708b4de7f86002d2d735a2dbf3b5b7f65692
      —
      Referenceremoved
      https://git.kernel.org/stable/c/3d205fe80f2181f0109150ad1fa06ee5bc046935
      —
      Referenceremoved
      https://git.kernel.org/stable/c/511d2b92f8d20de04acafab676150d26fb5c67f4
      —
      Referenceremoved
      https://git.kernel.org/stable/c/778b9dda4b24005a27bcd9c35c110bf8d7f259ca
      —
      Referenceremoved
      https://git.kernel.org/stable/c/ccdf4510a3873b14e5e348cdb038717996f09fda
      —
      Referenceremoved
      https://git.kernel.org/stable/c/d72650a4f334581b23a1892b888a4cb1be142f76
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/07ffe414a708ae60551401cec5d727ed156b8caf Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/10fc708b4de7f86002d2d735a2dbf3b5b7f65692 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/3d205fe80f2181f0109150ad1fa06ee5bc046935 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/511d2b92f8d20de04acafab676150d26fb5c67f4 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/778b9dda4b24005a27bcd9c35c110bf8d7f259ca Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/ccdf4510a3873b14e5e348cdb038717996f09fda Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/d72650a4f334581b23a1892b888a4cb1be142f76 Types: Patch
      —

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

    3. 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-2026-53384","role":"CISA Coordinator","options":[{"exploitation":"none"},{"automatable":"yes"},{"technicalImpact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T15:29:55.097049Z"}

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

    4. Record modifiedLinux

      1 individual change: Affected versions (publisher)

      Show the original change
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Affected versions (publisher)changed
      Linux, Linux
      Linux, Linux

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

    5. Reanalysis by NVDNVD

      Product mapping changed:
      • Linux Kernel (6.2 – before 6.6.144; 6.7 – before 6.12.95; 6.19 – before 7.0.14; 7.1 – before 7.1.2; 6.13 – before 6.18.38; 5.19 – before 6.1.177)
      Show the original change
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Product configurationchanged
      OR *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.2 up to (excluding) 6.6.144 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.7 up to (excluding) 6.12.95 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.19 up to (excluding) 7.0.14 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 7.1 up to (excluding) 7.1.2 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.13 up to (excluding) 6.18.38 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.9 up to (excluding) 6.1.177
      OR *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.2 up to (excluding) 6.6.144 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.7 up to (excluding) 6.12.95 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.19 up to (excluding) 7.0.14 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 7.1 up to (excluding) 7.1.2 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.13 up to (excluding) 6.18.38 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.19 up to (excluding) 6.1.177

      Source identifier: nvd@nist.gov

    Show 2 older changes

    1. Record modifiedLinux

      1 individual change: Affected versions (publisher)

      Show the original change
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Affected versions (publisher)changed
      Linux, Linux
      Linux, Linux

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

    2. ReceivedLinux

      Description added or changed

      Show 9 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Affected versions (publisher)added
      —
      Linux, Linux
      Descriptionadded
      —
      In the Linux kernel, the following vulnerability has been resolved: serial: 8250_dw: unregister 8250 port if clk_notifier_register() fails dw8250_probe() registers the 8250 port via serial8250_register_8250_port() and then, if the device has a clock, registers a clock notifier. If clk_notifier_register() fails, probe returns the error but leaves the 8250 port registered. The matching serial8250_unregister_port() lives in dw8250_remove(), which is not called when probe fails, so the port slot stays occupied until the device is rebound or the system is rebooted. The devm-allocated driver data is freed while the port still references it (via the saved private_data and serial_in/serial_out callbacks), so any access to that port slot before a rebind is a use-after-free hazard. Unregister the port on the clk_notifier_register() error path.
      Referenceadded
      —
      https://git.kernel.org/stable/c/07ffe414a708ae60551401cec5d727ed156b8caf
      Referenceadded
      —
      https://git.kernel.org/stable/c/10fc708b4de7f86002d2d735a2dbf3b5b7f65692
      Referenceadded
      —
      https://git.kernel.org/stable/c/3d205fe80f2181f0109150ad1fa06ee5bc046935
      Referenceadded
      —
      https://git.kernel.org/stable/c/511d2b92f8d20de04acafab676150d26fb5c67f4
      Referenceadded
      —
      https://git.kernel.org/stable/c/778b9dda4b24005a27bcd9c35c110bf8d7f259ca
      Referenceadded
      —
      https://git.kernel.org/stable/c/ccdf4510a3873b14e5e348cdb038717996f09fda
      Referenceadded
      —
      https://git.kernel.org/stable/c/d72650a4f334581b23a1892b888a4cb1be142f76

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

    Linked advisories

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