Use-after-free in Linux kernel - CVE-2026-89546
Published: September 12, 2026
Vulnerability identifier: #VU149265
CSH Severity: Medium
CVSS v4: 8.2 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-89546
CWE-ID: CWE-416
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to a use-after-free race condition in the SUNRPC backchannel request handling and NFS callback service teardown when a backchannel request completes while the callback service is being torn down. A remote attacker can cause a backchannel request to complete during callback-service teardown to cause a denial of service.
Affected software
Linux kernel
How to mitigate CVE-2026-89546
Install security update from vendor's repository.