NULL pointer dereference in Linux kernel - CVE-2026-23442
Published: April 6, 2026
Vulnerability identifier: #VU124929
CSH Severity: Medium
CVSS v4.0: 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/E:U/U:Green
CVE-ID: CVE-2026-23442
CWE-ID: CWE-476
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Linux Foundation
Affected software:
Linux kernel
Linux kernel
Detailed vulnerability description
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to a NULL pointer dereference in seg6_hmac_validate_skb() and ipv6_srh_rcv() when processing SRv6 paths on a device without IPv6 configuration. A remote attacker can send specially crafted IPv6 traffic to cause a denial of service.
The issue occurs when __in6_dev_get() returns NULL, such as on a device with no IPv6 configuration, including after device unregister or when the MTU is below the IPv6 minimum MTU.
How to mitigate CVE-2026-23442
Install security update from vendor's repository.