SB2026102384 - NULL pointer dereference in Linux kernel ipv4

Description

This security bulletin contains information about 1 vulnerability.

1) NULL pointer dereference (CVE-ID: CVE-2026-99073)

CWE-ID: CWE-476 - NULL Pointer Dereference

CVSSv4: 5.6 [CVSS:4.0/AV:L/AC:L/AT:P/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

The vulnerability allows a local privileged user to cause a denial of service by triggering a kernel NULL pointer dereference.

The vulnerability exists due to a NULL pointer dereference in fib_dump_info_fnhe() when an IPv4 forwarding information base dump runs concurrently with nexthop group replacement. A local privileged user can replace a nexthop group with fewer paths during a dump, causing fib_info_nhc() to return NULL that is subsequently dereferenced through nhc_flags, to cause a denial of service.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/21cba134c30c17ae55f468b5809336437df5d7e6
• https://git.kernel.org/stable/c/4f4afc07dcb2edd4f9afa36595373f8cdb9b58c2
• https://git.kernel.org/stable/c/b9a30bb7b831e8c5a47fadbdf1760918aaf009cc
• https://git.kernel.org/stable/c/f91e472821e32f58b03eb631e20a67157e2b928b