CVE-2026-80957 dm-pcache: detect a cycle in the last-kset chain during replay
A local attacker can cause a denial of service in the Linux kernel by forging a cyclic chain in the dm-pcache replay process.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-80957?
CVE-2026-80957 is a denial of service vulnerability in Linux, published on 11 Sep 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:
dm-pcache: detect a cycle in the last-kset chain during replay
cache_replay() follows the on-media last-kset chain by next_cache_seg_id with no cond_resched(). A forged chain that points back into a segment it has already visited makes the replay loop follow it forever.
Cap the last-kset hops at cache->n_segs; a valid chain visits each segment at most once.
Which versions are affected by CVE-2026-80957?
How do I fix CVE-2026-80957?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-80957 being exploited?
There is no known exploitation of CVE-2026-80957 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-80957, DEBIAN-CVE-2026-80957, GHSA-p2v2-4gmp-9rph, UBUNTU-CVE-2026-80957.