NULL pointer dereference in Linux kernel - CVE-2026-43496
Published: May 22, 2026
Vulnerability identifier: #VU132126
CSH Severity: Low
CVSS v4.0: 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
CVE-ID: CVE-2026-43496
CWE-ID: CWE-476
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vendor: Linux Foundation
Affected software:
Linux kernel
Linux kernel
Detailed vulnerability description
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.
How to mitigate CVE-2026-43496
Install security update from vendor's repository.
Sources
- https://git.kernel.org/stable/c/36aa34f42cb6842cf371f3a2d3e855d24fd57a50
- https://git.kernel.org/stable/c/458d5615272d3de535748342eb68ca492343048c
- https://git.kernel.org/stable/c/587dcf970a525f543d8b5855d9f37a4ca97b76ef
- https://git.kernel.org/stable/c/8d09618840b99ef00154d3e731ce9b11e096196d
- https://git.kernel.org/stable/c/ce051eede433f876d322ac3550a36a3c6fc4c231