SB2026102398 - Race condition in Linux kernel ipv6
Published: October 23, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Race condition (CVE-ID: CVE-2026-99070)
CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
CVSSv4: 0 [CVSS:4.0/AV:L/AC:L/AT:P/PR:H/UI:N/VC:N/VI:N/VA:N/SC:N/SI:N/SA:N]
The vulnerability allows a local privileged user to trigger spurious kernel warnings.
The vulnerability exists due to a race condition in the Linux kernel IPv6 route notification function fib6_info_hw_flags_set() when calculating notification sizes and filling notification buffers using separate snapshots. A local privileged user can trigger concurrent nexthop group replacement during notification construction to cause rt6_fill_node() to return -EMSGSIZE and trigger an unwarranted kernel warning.
The race requires nexthop compatibility mode to be enabled.
Remediation
Install update from vendor's website.
References
- https://git.kernel.org/stable/c/291fe0bafee78c95f9f2e7f579f17793fd5a1e5a
- https://git.kernel.org/stable/c/4ac7d92a4698e34e614c254359665b9de1f65283
- https://git.kernel.org/stable/c/7b112bd43f1172fb152e848570a957467008a5ae
- https://git.kernel.org/stable/c/8a3b935b6b6037eefb36bd27a60793a008358e8d
- https://git.kernel.org/stable/c/c97426ec649d99596d8969e1a052c16b14b7b485