VulnerabilityPublished 18 Oct 2026

CVE-2026-98866: Linux kernel · sched/cache: Introduce task_struct->sched_cache_grp to fix UAF

Source GCVE Database

Authoritative record:CVE-2026-98866· High

Not known to be exploited : upgrade to b636fef85bda7d1bab9c0a45067ab1508d79d946 or 9436130e6da72af63289a4acb3aa0c1df07a3928 soon.

Data as of 26 Oct 2026, 12:55 UTC

Severity

High

Rated by Threat Radar · CVSS not yet scored by NVD

EPSS: 0.1% chance of exploitation in 30 days – higher than 3% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in b636fef85bda7d1bab9c0a45067ab1508d79d946, 9436130e6da72af63289a4acb3aa0c1df07a3928

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-3r69-998r-q4c2

What to do

Upgrade Linux kernel to b636fef85bda7d1bab9c0a45067ab1508d79d946 or 9436130e6da72af63289a4acb3aa0c1df07a3928.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ df0d98475954d655571979aa061ecb07d7e00392, < b636fef85bda7d1bab9c0a45067ab1508d79d946	Fixed in b636fef85bda7d1bab9c0a45067ab1508d79d946
LinuxLinux	Affected ≥ df0d98475954d655571979aa061ecb07d7e00392, < 9436130e6da72af63289a4acb3aa0c1df07a3928	Fixed in 9436130e6da72af63289a4acb3aa0c1df07a3928
LinuxLinux	Affected =7.2	Fixed in–
Red Hatredhat/kernel`pkg:rpm/redhat/kernel`Other threats	Affected =7.2	Fixed in–

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

AI-suggested

An official fix has been implemented in the Linux kernel by introducing task_struct->sched_cache_grp and refactoring reference management. Users should update to the fixed kernel versions once available. Patch status is confirmed as fixed in the vendor source. No additional mitigations are required beyond applying the official fix.

Description

A use-after-free (UAF) vulnerability in the Linux kernel scheduler was addressed by introducing a new pointer task_struct->sched_cache_grp. This change decouples scheduler hot-path accesses from the memory management structure, fixing the UAF issue that occurred when accessing the scheduler cache group through a task whose memory management structure was being switched.

References

Community reviews

Loading reviews…