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PatchSiren cyber security CVE debrief

CVE-2026-53180 Linux CVE debrief

A HIGH severity vulnerability, CVE-2026-53180, was resolved in the Linux kernel. The vulnerability was caused by a livelock in tmigr_handle_remote_up(), which could lead to a denial-of-service attack. The issue arose from the incorrect assumption that the local softirq path had already handled the CPU's timers. This assumption was wrong because jiffies could advance after handling the CPU's global timers and before evaluating the expiry times. As a result, a timer that expired after the CPU local timer wheel advanced was ignored, and its callback was never invoked or removed from the timer wheel. The vulnerability had a CVSS score of 7.5 and was patched by calling timer_expire_remote() unconditionally.

Vendor
Linux
Product
Unknown
CVSS
HIGH 7.5
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-25
Original CVE updated
2026-07-06
Advisory published
2026-06-25
Advisory updated
2026-07-06

Who should care

System administrators and security teams responsible for Linux kernel-based systems should be aware of this vulnerability. They should check their systems for exposure and apply the patch to prevent potential denial-of-service attacks. Linux kernel developers and maintainers should also review the patch and ensure it is integrated into their systems.

Technical summary

The vulnerability was caused by a livelock in tmigr_handle_remote_up() due to an incorrect assumption about the handling of CPU timers. The issue led to a timer being ignored and its callback never invoked or removed from the timer wheel. The vulnerability was resolved by calling timer_expire_remote() unconditionally, which has minimal overhead for the common case. The patch ensures that timers are properly handled and callbacks are invoked.

Defensive priority

Apply the patch to prevent potential denial-of-service attacks. Review system logs for signs of exploitation.

Recommended defensive actions

  • Apply the patch by updating the Linux kernel to the latest version.
  • Review system logs for signs of exploitation.
  • Check system configurations for exposure.
  • Monitor system performance for potential denial-of-service attacks.
  • Ensure Linux kernel developers and maintainers review and integrate the patch.

Evidence notes

The vulnerability was resolved by calling timer_expire_remote() unconditionally. The patch has minimal overhead for the common case. The issue arose from an incorrect assumption about the handling of CPU timers. The vulnerability had a CVSS score of 7.5 and was classified as HIGH severity.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-53180 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-53180

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-53180 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-53180

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/07b3b83587fb3012619f4439389b64a955fc7836

    416baaa9-dc9f-4396-8d5f-8c081fb06d67

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/1d6c2062b77be09ec15d6bf637b2e2221c4482fc

    416baaa9-dc9f-4396-8d5f-8c081fb06d67

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/d338e61ea94052a786aac9f58e9f0d8520afa0fd

    416baaa9-dc9f-4396-8d5f-8c081fb06d67

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/d486b4934a8e504376b85cdb3766f306d57aff5b

    416baaa9-dc9f-4396-8d5f-8c081fb06d67

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.