SB2026072820 - Use-after-free in Linux kernel ipv6



SB2026072820 - Use-after-free in Linux kernel ipv6

Published: July 28, 2026

Security Bulletin ID SB2026072820
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Remote access
Highest impact Denial of service

Breakdown by Severity

Medium 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Use-after-free (CVE-ID: CVE-2026-64554)

CWE-ID: CWE-416 - Use After Free

CVSSv4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/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 br_ip6_fragment() when processing crafted IPv6 packets on a cloned skb. A local user can send a specially crafted packet to cause a denial of service.

The issue results from dereferencing a stale prevhdr pointer after skb_checksum_help() reallocates the skb head, and the resulting write can trigger a kernel panic.


Remediation

Install update from vendor's website.