CVE-2026-80958 dm-pcache: clamp the tail kset read to the segment data region
A local attacker can read sensitive kernel memory by triggering a buffer over-read in the dm-pcache module's tail kset handling.
- 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-2026-80958?
CVE-2026-80958 is a high-severity 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: clamp the tail kset read to the segment data region
The tail-kset read in cache_replay(), the writeback worker and the GC worker bounds its length by PCACHE_SEG_SIZE - seg_off, the raw segment size rather than the data region. A tail near the segment end reads past the segment data into the following control area.
Clamp the read to cache_seg_remain(), the data region.
Which versions are affected by CVE-2026-80958?
How do I fix CVE-2026-80958?
Apply the vendor's patch.
Is CVE-2026-80958 being exploited?
There is no known exploitation of CVE-2026-80958 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-80958, DEBIAN-CVE-2026-80958, GHSA-hh69-ghmv-95j7, UBUNTU-CVE-2026-80958.