Missing Release of Resource after Effective Lifetime in Linux kernel - CVE-2026-89491
Published: September 12, 2026
Vulnerability identifier: #VU149326
CSH Severity: Low
CVSS v4: 0 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-89491
CWE-ID: CWE-772
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to leave heartbeat regions unprotected on subsequent mounts.
The vulnerability exists due to improper error handling in o2hb_region_inc_user() when heartbeat region pinning fails partway through processing. A local user can invoke heartbeat region user registration during a pinning failure to leave heartbeat regions unprotected on subsequent mounts.
Partially pinned regions are not released, and the dependent-user counter remains incremented.
Affected software
Linux kernel
How to mitigate CVE-2026-89491
Install security update from vendor's repository.