SB2026080622 - Use-after-free in Linux kernel ipv4
Published: August 6, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Use-after-free (CVE-ID: CVE-2026-64572)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 5.6 [CVSS:4.0/AV:L/AC:L/AT:P/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a local privileged user to cause a denial of service.
The vulnerability exists due to a use-after-free in fib_table_lookup() and the IPv4 FIB alias list handling in fib_trie.c when processing concurrent route insertion failure and lookup operations. A local privileged user can trigger a route insertion error path and perform a concurrent lookup to cause a denial of service.
Exploitation requires CAP_NET_ADMIN and a registered FIB notifier that can reject a route, such as when an IPv4 FIB resource is exhausted on a netdevsim device.
Remediation
Install update from vendor's website.
References
- https://git.kernel.org/stable/c/8150b5365f026e72250cacc527ea00be30f40105
- https://git.kernel.org/stable/c/b8d2ea75c76abcd0d72679c2f488271f573e32fb
- https://git.kernel.org/stable/c/cb8be318b4432abd88d3172ec157330f27a5f7a7
- https://git.kernel.org/stable/c/d007056868723de9c0cc3f5ffaad47a8d468b9a4
- https://git.kernel.org/stable/c/f2f152e94a67bc746afaf05a1b2702c195553112