VulnerabilityPublished 18 Oct 2026

CVE-2026-98865: Linux kernel · sched_ext: Don't run ops.dequeue() with a DSQ lock held

Source GCVE Database

Authoritative record:CVE-2026-98865· Medium

Not known to be exploited : upgrade to fe499ae9da46e297f578d4346c4c8e338c3118db or cb86607ada73185f321baa7f9d94a08a3a40bbf5 when convenient.

Data as of 26 Oct 2026, 12:55 UTC

Severity

Medium

Rated by Threat Radar · CVSS not yet scored by NVD

EPSS: 0.1% chance of exploitation in 30 days – higher than 6% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in fe499ae9da46e297f578d4346c4c8e338c3118db, cb86607ada73185f321baa7f9d94a08a3a40bbf5

Exploitation evidence

Disclosed: evidence found.
CVE published 18 Oct 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-2w8f-349m-66qf

What to do

Upgrade Linux kernel to fe499ae9da46e297f578d4346c4c8e338c3118db or cb86607ada73185f321baa7f9d94a08a3a40bbf5.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ ebf1ccff79c43f860cbd2f9d6cfab9a462d0cb2d, < fe499ae9da46e297f578d4346c4c8e338c3118db	Fixed in fe499ae9da46e297f578d4346c4c8e338c3118db
LinuxLinux	Affected ≥ ebf1ccff79c43f860cbd2f9d6cfab9a462d0cb2d, < cb86607ada73185f321baa7f9d94a08a3a40bbf5	Fixed in cb86607ada73185f321baa7f9d94a08a3a40bbf5
LinuxLinux	Affected =7.1	Fixed in–

AI-suggested

A fix has been implemented in the Linux kernel to move the ops.dequeue() call after the DSQ unlock on all affected paths, preventing the deadlock condition. Users should update to the patched kernel version once available. Patch status is not explicitly confirmed in the provided data; check the vendor advisory or Linux kernel mailing lists for the official fix and updated versions.

Description

A deadlock vulnerability in the Linux kernel scheduler extension (sched_ext) was resolved by changing when ops.dequeue() is invoked relative to DSQ locks. The issue caused self-deadlocks when ops.dequeue() was called while holding a source user DSQ lock, particularly affecting BPF schedulers that lock the source user DSQ during iteration. The fix moves the ops.dequeue() call to after the DSQ unlock to prevent deadlocks and ensures the callback is invoked exactly once.

References

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