SB20260824241 - Use-after-free in Linux kernel ipv4



SB20260824241 - Use-after-free in Linux kernel ipv4

Published: August 24, 2026

Security Bulletin ID SB20260824241
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-2026-74589)

CWE-ID: CWE-416 - Use After Free

CVSSv4: 6.8 [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]


The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to use-after-free in tcp_bpf_send_verdict() and tcp_bpf_sendmsg_redir() when processing concurrent sendmsg() operations with a cached redirect verdict. A local user can trigger concurrent socket send operations to cause a denial of service.

The issue occurs when apply_bytes keeps the cached verdict active, allowing one thread to release the redirect socket reference while another thread still uses a stale pointer.


Remediation

Install update from vendor's website.