SB2026080622 - Use-after-free in Linux kernel ipv4



SB2026080622 - Use-after-free in Linux kernel ipv4

Published: August 6, 2026

Security Bulletin ID SB2026080622
CSH Severity
Low
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Local access
Highest impact Denial of service

Breakdown by Severity

Low 100%
  • 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.