Time-of-check Time-of-use (TOCTOU) Race Condition in Linux kernel - CVE-2026-45927
Published: May 28, 2026
Vulnerability identifier: #VU132562
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2026-45927
CWE-ID: CWE-367
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vendor: Linux Foundation
Affected software:
Linux kernel
Linux kernel
Detailed vulnerability description
The vulnerability allows a local user to bypass integrity verification.
The vulnerability exists due to a time-of-check time-of-use race condition in bpf_map_get_info_by_fd when calculating and caching the map hash before the map is frozen. A local user can modify map contents after the hash is cached to bypass integrity verification.
Exploitation requires a trusted loader to verify the cached hash while loading the modified map contents.
How to mitigate CVE-2026-45927
Install security update from vendor's repository.