VulnerabilityPublished 11 Sep 2026Updated 5 Oct 2026

CVE-2026-89517: Linux kernel · sched_ext: Fix rq->core_pick corruption under core scheduling

Affects Linux kernelSource GCVE Database

Not known to be exploited.

Data as of 26 Oct 2026, 13:47 UTC

Severity

Medium

Rated by Threat Radar · CVSS not yet scored by NVD

EPSS: 0.1% chance of exploitation in 30 days – higher than 9% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

Exploitation evidence

Disclosed: evidence found.
CVE published 11 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

ghsa-xg94-9m82-xc6c

What to do

Affected software

Product	Affected	Fixed in
Ubuntu 26.04 LTSlinux`pkg:deb/ubuntu/linux?arch=source&distro=resolute`Other threats	Affected 6.17.0-5.5 – 7.0.0-38.38 23 affected builds	Fixed in–
Ubuntu 26.04 LTSlinux-aws`pkg:deb/ubuntu/linux-aws?arch=source&distro=resolute`Other threats	Affected 6.17.0-1002.2 – 7.0.0-1014.14 15 affected builds	Fixed in–
Ubuntu 26.04 LTSlinux-azure`pkg:deb/ubuntu/linux-azure?arch=source&distro=resolute`Other threats	Affected 6.17.0-1003.3 – 7.0.0-1017.17 15 affected builds	Fixed in–
Ubuntu 26.04 LTSlinux-azure-fde`pkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resolute`Other threats	Affected 7.0.0-1003.3 – 7.0.0-1016.16 9 affected builds	Fixed in–
Ubuntu 26.04 LTSlinux-gcp`pkg:deb/ubuntu/linux-gcp?arch=source&distro=resolute`Other threats	Affected 6.17.0-1002.2 – 7.0.0-1014.14 13 affected builds	Fixed in–
Ubuntu 26.04 LTSlinux-gke`pkg:deb/ubuntu/linux-gke?arch=source&distro=resolute`Other threats	Affected 7.0.0-1002.3 – 7.0.0-1008.9 6 affected builds	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

A fix has been implemented in the Linux kernel to address this issue. Users should apply the updated kernel versions that include this patch. Since this is a kernel-level fix, upgrading to a patched kernel release is the recommended remediation. No additional mitigations are indicated.

Description

A vulnerability in the Linux kernel's core scheduling implementation could cause corruption of the rq->core_pick state, leading to NULL pointer dereferences or deadlocks. This occurs due to interleaved task selections on SMT siblings when the rq lock is released and reacquired improperly. The issue can cause kernel hangs under certain load conditions. The flaw has been fixed by ensuring that task selection retries if the rq lock is dropped during dispatch, maintaining consistent state. Several specific Linux kernel versions are affected.

Impact

The vulnerability can cause kernel crashes due to NULL pointer dereferences or deadlocks resulting in hard hangs. This affects system stability on affected Linux kernel versions, particularly on SMT-enabled systems under specific load patterns. There is no indication of remote code execution or privilege escalation from the provided data.

Summary

The Linux kernel vulnerability (CVE-2026-89517) involves corruption of the rq->core_pick field under core scheduling. Core scheduling's pick_next_task() function selects tasks to run on SMT siblings under a shared core-wide rq lock. Originally, the lock was held continuously during selection, but a change introduced dispatching inside the pick function, which can release the rq lock. This allows interleaved selections on the same core to corrupt each other's state, causing NULL dereferences or deadlocks. The fix makes pick_next_task() return RETRY_TASK whenever dispatch releases the rq lock, ensuring selections commit only when the lock is held continuously. Additional logic prevents unnecessary dispatches and ensures balance callbacks run in the correct context. The patch addresses kernel hangs caused by these race conditions.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 25 Oct 2026, 01:59 UTC

Technical details

References

Community reviews

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