Out-of-bounds read in Linux kernel - CVE-2026-74739
Published: August 27, 2026
Vulnerability identifier: #VU145989
CSH Severity: Low
CVSS v4: 8.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-74739
CWE-ID: CWE-125
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to disclose sensitive information.
The vulnerability exists due to an out-of-bounds read in u32_bind_class() when processing cls_u32 walker callback entries. A local user can trigger class binding on a hash table entry that is incorrectly treated as a tc_u_knode to disclose sensitive information.
The issue occurs because u32_walk() can enumerate both tc_u_hnode and tc_u_knode objects, but the affected code unconditionally treats the callback argument as a tc_u_knode.
Affected software
Linux kernel
How to mitigate CVE-2026-74739
Install security update from vendor's repository.
Linux kernel - update to 7.0 rc3
External References
- https://git.kernel.org/stable/c/19d114b93c94bdef70496f26685c2a6b242f41b3
- https://git.kernel.org/stable/c/31f26a95eeee926946809ac456c61a3217936a62
- https://git.kernel.org/stable/c/594a064d603202b9ee21e07679d854e5c1750cc4
- https://git.kernel.org/stable/c/6d3724e616faf952c3adcf8414fc21a828ef3709
- https://git.kernel.org/stable/c/e71f8e9ed6f311410b14741f6012afe01869c0fa
- https://git.kernel.org/stable/c/ec5f3005586a785689fd568361b0c5925cb1548b