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PatchSiren cyber security CVE debrief

CVE-2026-52980 Linux CVE debrief

A yield-triggered crash can occur when a newly forked sched_entity enters the fair class with an unexpectedly set se->rel_deadline. The issue arises from __sched_fork() not clearing rel_deadline, leading to an abnormally large deadline and potential NULL dereference. This vulnerability affects Linux kernel deployments and requires prompt attention from maintainers and users.

Vendor
Linux
Product
Unknown
CVSS
MEDIUM 5.5
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-24
Original CVE updated
2026-07-14
Advisory published
2026-06-24
Advisory updated
2026-07-14

Who should care

Linux kernel users, maintainers, and security teams should be aware of this vulnerability and ensure they update to a patched version. Affected deployments may require immediate attention to prevent potential crashes and NULL dereferences.

Technical summary

The Linux kernel vulnerability CVE-2026-52980 is caused by the failure to clear se->rel_deadline when initializing forked entities in __sched_fork(). This can lead to an abnormally large deadline, causing issues with EEVDF eligibility calculation and potentially resulting in a NULL dereference. Linux kernel users and maintainers should be aware of this vulnerability and ensure they update to a patched version.

Defensive priority

High priority for Linux kernel maintainers and users to apply patches and review deployments.

Recommended defensive actions

  • Apply patches to clear rel_deadline in __sched_fork()
  • Update to a patched Linux kernel version
  • Monitor for potential issues with EEVDF eligibility calculation
  • Review compensating controls for exposed systems while remediation is scheduled and verified
  • Check relevant monitoring, detection, and logs for exposed assets that need extra review
  • Track exceptions, retest remediated assets, and close the item only after evidence is documented
  • Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record was published on 2026-06-24T17:17:08.610Z and last modified on 2026-07-10T19:24:19.850Z. The NVD entry is currently Awaiting Analysis. Linux kernel users should verify their deployments and apply patches or mitigations as necessary. Evidence limits suggest that affected scope and severity may be under review.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-52980 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-52980

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

  • CVE-2026-52980 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-52980

    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/3da56dc063cd77b9c0b40add930767fab4e389f3

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

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/8f4a16200785f49cf02c5b71bdfe7a9dab63f23a

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

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/c71bf35caba12bfd9bc23e32b0bcd9e02d1cf1ac

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

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/f3c16e1f4a314a20717ab90a41885f8111a242ab

    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.