Use-after-free in Linux kernel - CVE-2026-90301
Published: September 18, 2026
Vulnerability identifier: #VU151184
CSH Severity: Low
CVSS v4: 2.3 [CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-90301
CWE-ID: CWE-416
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to cause a denial of service.
The vulnerability exists due to use-after-free in the OCFS2 o2hb heartbeat region handlers and delayed timeout work when processing heartbeat negotiation messages while a heartbeat region is being initialized or torn down. A remote user can send a heartbeat negotiation message to cause a denial of service.
Exploitation requires racing heartbeat region lifecycle operations with an in-flight o2net callback or delayed work.
Affected software
Linux kernel
How to mitigate CVE-2026-90301
Install security update from vendor's repository.