CVE-2026-54370 acl < 2.4.0 TOCTOU Symlink Traversal via getfacl/setfacl/chacl
Local attackers can escalate privileges by exploiting a race condition in ACL utilities to redirect file operations to arbitrary files.
- 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-2026-54370?
CVE-2026-54370 is a high-severity vulnerability in acl, published on 29 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
acl before version 2.4.0 contains a time-of-check to time-of-use (TOCTOU) race condition vulnerability that allows local attackers to escalate privileges by replacing a pathname component with a symbolic link between an lstat() check and subsequent symlink-following operations such as stat(), chown(), chmod(), acl_get_file(), and acl_set_file(). Attackers who control a pathname component can redirect file access control list operations to arbitrary files when getfacl, setfacl, or chacl is invoked by a privileged process over an attacker-controlled path, resulting in local privilege escalation.
Weakness: CWE-367
Which versions are affected by CVE-2026-54370?
How do I fix CVE-2026-54370?
Upgrade to a fixed version.
Is CVE-2026-54370 being exploited?
There is no known exploitation of CVE-2026-54370 in the wild and no public exploit code.
Sources
Also known as AZL-91394, DEBIAN-CVE-2026-54370, ECHO-ae30-49be-9cc5, GHSA-r45p-762r-6pqj, ROOT-OS-DEBIAN-11-CVE-2026-54370, ROOT-OS-DEBIAN-12-CVE-2026-54370 and 2 more.