SB20260720224 - Use-after-free in Linux kernel netfilter



SB20260720224 - Use-after-free in Linux kernel netfilter

Published: July 20, 2026

Security Bulletin ID SB20260720224
CSH Severity
High
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Remote access
Highest impact Denial of service

Breakdown by Severity

High 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Use-after-free (CVE-ID: CVE-2026-64007)

CWE-ID: CWE-416 - Use After Free

CVSSv4: 8.8 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N]


The vulnerability allows a remote attacker to cause memory corruption or a denial of service.

The vulnerability exists due to a use-after-free in synproxy_tstamp_adjust() in the netfilter synproxy implementation when processing crafted TCP packets that trigger header rewriting on a cloned or non-linear skb. A remote attacker can send a specially crafted packet to cause memory corruption or a denial of service.

The issue affects checksum updates after the packet buffer is made writable, which can result in a write to freed slab memory or a transmitted packet with a stale checksum.


Remediation

Install update from vendor's website.