SB2026052209 - NULL pointer dereference in Linux kernel sched



SB2026052209 - NULL pointer dereference in Linux kernel sched

Published: May 22, 2026

Security Bulletin ID SB2026052209
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) NULL pointer dereference (CVE-ID: CVE-2026-43496)

CWE-ID: CWE-476 - NULL Pointer Dereference

CVSSv4: 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/E:U/U:Clear


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

The vulnerability exists due to a null pointer dereference in the sch_red qdisc dequeue logic when processing queued packets through child qdiscs whose peek() callback is qdisc_peek_dequeued(). A local user can trigger network traffic through a crafted qdisc hierarchy to cause a kernel panic.

The issue occurs when red qdisc has child qdiscs such as qfq and a parent qdisc retrieves an skb using a peek operation followed by dequeue.


Remediation

Install update from vendor's website.