Use-after-free in Linux kernel - CVE-2026-89990
Published: September 16, 2026
Vulnerability identifier: #VU150291
CSH Severity: High
CVSS v4: 9.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-89990
CWE-ID: CWE-416
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to execute arbitrary code.
The vulnerability exists due to use-after-free in ceph_mds_check_access() when a concurrent MDS session reopen occurs while access is being checked. A remote attacker can trigger concurrent access checking and MDS session reopening to execute arbitrary code.
Affected software
Linux kernel
How to mitigate CVE-2026-89990
Install security update from vendor's repository.