Use-after-free in Linux kernel - CVE-2026-46099
Published: May 27, 2026
Linux kernel
Detailed vulnerability description
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to a use-after-free in seg6 and rpl lwtunnels when processing IPv6 routing lookups and caching a NOREF destination entry. A local user can trigger a race condition to cause a denial of service.
Exploitation requires PREEMPT_RT without PREEMPT_RT_NEEDS_BH_LOCK and a concurrent task able to release a shared nexthop per-cpu route entry.
How to mitigate CVE-2026-46099
Sources
- https://git.kernel.org/stable/c/52f9db67f8f35f436366cf4980b4f0a2583d0ef0
- https://git.kernel.org/stable/c/6bd17925bd6866027a6555db17905b9fc073d38d
- https://git.kernel.org/stable/c/9dd5481f960e337b81d7dfe429529495c1c481c0
- https://git.kernel.org/stable/c/b778b6d095421619c331fd2d7751143cd5387103
- https://git.kernel.org/stable/c/f9c52a6ba9780bd27e0bf4c044fd91c13c778b6e