SB2026100952 - Use-after-free in Linux kernel core



SB2026100952 - Use-after-free in Linux kernel core

Published: October 9, 2026

Security Bulletin ID SB2026100952
CSH Severity
Low
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Local access
Highest impact Data manipulation

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-2026-98383)

CWE-ID: CWE-416 - Use After Free

CVSSv4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]


The vulnerability allows a local user to corrupt kernel memory.

The vulnerability exists due to use-after-free in BPF LWT_SEG6LOCAL handling when performing post-program SRH validation. A local user can run an LWT_SEG6LOCAL program that invalidates its cached SRH with bpf_lwt_seg6_adjust_srh() and then calls bpf_skb_pull_data() to corrupt kernel memory.

Reallocation of skb->head leaves the per-CPU SRH pointer dangling, and subsequent SRH validation writes through that pointer.


Remediation

Install update from vendor's website.