CVE-2026-80962 dm-pcache: validate geometry fields from on-disk cache_info
A local attacker with CAP_SYS_ADMIN can trigger out-of-bounds memory access in the Linux kernel dm-pcache module via crafted on-disk metadata, potentially leading to code execution or privilege escalation.
- 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-2026-80962?
CVE-2026-80962 is a high-severity memory corruption 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: validate geometry fields from on-disk cache_info
cache_segs_init() iterates cache_info->n_segs times indexing cache->segments[], which is sized to the cache device geometry, and get_seg_id() takes each segment id from the on-media cache_info and the per-segment next_seg link. Both come from cache device metadata that is only CRC-protected with a fixed public seed, so whoever supplies the cache device on a table load (CAP_SYS_ADMIN) controls them: an oversized n_segs or an out-of-range id drives an out-of-bounds access of cache->segments[] and a wild CACHE_DEV_SEGMENT() pointer into the device mapping -- an out-of-bounds read and write from on-disk data.
Reject an n_segs that exceeds the device segment count and a segment id that is out of range before either is used. Valid metadata is unaffected.
Which versions are affected by CVE-2026-80962?
How do I fix CVE-2026-80962?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-80962 being exploited?
There is no known exploitation of CVE-2026-80962 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-80962, DEBIAN-CVE-2026-80962, GHSA-mv2p-grx7-v5rf, UBUNTU-CVE-2026-80962.