Local privilege escalation via PSI timer use-after-free
Published Aug 22, 2026 · Updated Aug 25, 2026
Use-after-free in the Linux kernel PSI subsystem allows local users to escalate privileges or crash the operating system. psi_schedule_rtpoll_work can rearm rtpoll_timer after last-trigger teardown, so poll_timer_fn accesses a freed psi_group. Reachability requires writable PSI trigger files in a delegated cgroup v2 hierarchy and CAP_SYS_RESOURCE, which a user namespace can supply.
Summary
What happened
Use-after-free in the Linux kernel PSI subsystem allows local users to escalate privileges or crash the operating system. psi_schedule_rtpoll_work can rearm rtpoll_timer after last-trigger teardown, so poll_timer_fn accesses a freed psi_group. Reachability requires writable PSI trigger files in a delegated cgroup v2 hierarchy and CAP_SYS_RESOURCE, which a user namespace can supply.
The record
- CVE
- CVE-2026-74594
- Published
- Aug 22, 2026
- Updated
- Aug 25, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Aug 22, 2026CVE publishedPublication date reported by the CVE source.
- Aug 25, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=5.10.50 <5.10.266
- Affected versionversion=5.12.17 <5.13
- Affected versionversion=5.13.2 <5.14
- Affected versionversion=5.14
- Affected versionversion=6bfcb6178925b1fd28c102e53d403091b8f49396 <4addb102154b7cf6e2310ccbe20c3c08619e520d
- Affected versionversion=8f91efd870ea5d8bc10b0fcc9740db51cd4c0c83 <1e5ca82eee59caca6988f9d6e859786aab8a5fa0
- Affected versionversion=8f91efd870ea5d8bc10b0fcc9740db51cd4c0c83 <310b5a537a78c358a4cd244bd767c1a517a05459
- Affected versionversion=8f91efd870ea5d8bc10b0fcc9740db51cd4c0c83 <5457025fa8ca3c0d2732109513de839e3e797190
- Affected versionversion=8f91efd870ea5d8bc10b0fcc9740db51cd4c0c83 <611e7821c4f83a671455658797336faecc3a5196
- Affected versionversion=8f91efd870ea5d8bc10b0fcc9740db51cd4c0c83 <8037c5b2b2a447df52542f4d8535895d837bdcbd
- Affected versionversion=8f91efd870ea5d8bc10b0fcc9740db51cd4c0c83 <806fcff98c1d7cb3c1dc0015e55ebdbe819e6b08
- Affected versionversion=8f91efd870ea5d8bc10b0fcc9740db51cd4c0c83 <894a9300d7fb2e2951da92e565ae6de7ddfb0a69
- Affected versionversion=979965c33f734a1666af67900408f997ac669c23
- Affected versionversion=e1e5e263bbe0e6e9c3db36aa48a3c8acf546fa49
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What is affected?
Published CVSS scores
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Attacks
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