CVE-2026-88265 Crun: crun: /dev/null symlink follow during stdio reopen allows host bind-mount write and chown
Attackers can exploit symlink following in crun to write to host bind-mounts and change file ownership, requiring non-default /dev mounts.
- 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-2026-88265?
CVE-2026-88265 is a medium-severity path traversal vulnerability in Red Hat Enterprise Linux 10, published on 10 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
A flaw was found in crun. After pivot_root, reopening /dev/null for stdio can follow a symlink and attach a host file to container stdio, then change that file's ownership. Affected versions are crun 1.29.1 and earlier. Default configurations that mount a fresh /dev are not exposed. No fixed release is available yet.
Weakness: CWE-59
Which versions are affected by CVE-2026-88265?
How do I fix CVE-2026-88265?
No fix published yet.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2026-88265 being exploited?
There is no known exploitation of CVE-2026-88265 in the wild and no public exploit code.
Sources
Also known as AZL-101102, BELL-CVE-2026-88265, DEBIAN-CVE-2026-88265, GHSA-cwhr-hwj2-cjrp, UBUNTU-CVE-2026-88265.