NULL pointer dereference in Linux kernel - CVE-2026-46086
Published: May 27, 2026
Vulnerability identifier: #VU132396
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2026-46086
CWE-ID: CWE-476
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 cause a denial of service.
The vulnerability exists due to a null pointer dereference in br_fdb_fillbuf() when reading bridge forwarding database entries through the brforward_read() sysfs path during a concurrent local FDB update. A local user can trigger concurrent access to cause a denial of service.
The issue arises because RCU readers can observe inconsistent values of f->dst across a check and a later dereference.
How to mitigate CVE-2026-46086
Install security update from vendor's repository.
Sources
- https://git.kernel.org/stable/c/0b9e4bbfb7c949151e3acd44ed4aa33614d2e110
- https://git.kernel.org/stable/c/5424e678f9b304e148cf5dcc047cffc7a56a3bb5
- https://git.kernel.org/stable/c/81af4137a30c4c2dc694dea8cacb180bd66000ef
- https://git.kernel.org/stable/c/9a2d9d4e657b23dc21f24cf139e3aeff0b61341f
- https://git.kernel.org/stable/c/df4601653201de21b487c3e7fffd464790cab808