CVE-2026-52930 ipc/shm: serialize orphan cleanup with shm_nattch updates
A race condition in Linux kernel shared memory cleanup allows attackers to cause a denial of service by triggering inconsistent state during orphaned segment destruction.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-52930?
CVE-2026-52930 is a medium-severity vulnerability in Linux kernel, published on 24 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
ipc/shm: serialize orphan cleanup with shm_nattch updates
shm_destroy_orphaned() walks the shm idr under shm_ids(ns).rwsem, but that does not serialize all fields tested by shm_may_destroy(). In particular, shm_nattch is updated while holding shm_perm.lock, and attach paths can do that without holding the rwsem.
Do not decide that an orphaned segment is unused before taking the object lock. Move the shm_may_destroy() check under shm_perm.lock, matching the other destroy paths, and unlock the segment when it no longer qualifies for removal.
Which versions are affected by CVE-2026-52930?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-52930?
Apply the vendor's patch.
Is CVE-2026-52930 being exploited?
There is no known exploitation of CVE-2026-52930 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-90429, BELL-CVE-2026-52930, DEBIAN-CVE-2026-52930, GHSA-5g46-hmw3-w78x, ROOT-OS-DEBIAN-11-CVE-2026-52930, ROOT-OS-DEBIAN-12-CVE-2026-52930 and 3 more.