Use-after-free in Linux kernel - CVE-2026-89654
Published: September 12, 2026
Vulnerability identifier: #VU149152
CSH Severity: Low
CVSS v4: 0 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-89654
CWE-ID: CWE-416
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to cause a use-after-free.
The vulnerability exists due to missing session reference counting in check_new_map() when processing MDS session map updates. A local user can trigger a race between session map processing and session teardown to cause a use-after-free.
Affected software
Linux kernel
How to mitigate CVE-2026-89654
Install security update from vendor's repository.
Linux kernel - update to 7.0 rc3