NULL pointer dereference in Linux kernel - CVE-2026-89561
Published: September 12, 2026
Vulnerability identifier: #VU149251
CSH Severity: Medium
CVSS v4: 8.2 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-89561
CWE-ID: CWE-476
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to a null pointer dereference in ipv6_rpl_srh_rcv() when processing RPL segment routing packets after the receiving interface's IPv6 device pointer has been cleared during an MTU transition. A remote attacker can send RPL segment routing packets during the MTU transition to cause a denial of service.
Affected software
Linux kernel
How to mitigate CVE-2026-89561
Install security update from vendor's repository.