Vulnerability in Acl Project
CVE-2026-54370
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.
Vulnerability class: TOCTOU (Time-of-Check to Time-of-Use)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.3 (Medium). Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N.
EPSS exploit prediction
EPSS: 0.001 (1.2th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 1st percentile — 1.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.001 · newest: 0.001 · change: +0.000
Affected products
- Acl Project — versions 0
Weakness classification (CWE)
References
- cgit.git.savannah.nongnu.org/cgit/acl.git/commit/ (patch)
- cgit.git.savannah.nongnu.org/cgit/acl.git/commit/ (issue-tracking)
- www.vulncheck.com/advisories/acl-toctou-symlink-traversal-via-getfacl-setfacl-c… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-54370?
- CVE-2026-54370 is a medium-severity vulnerability in Acl Project, classified under Time-of-check Time-of-use (TOCTOU) Race Condition. CVSS score: 6.3/10. Published 2026-06-29.
- How severe is CVE-2026-54370?
- Medium severity. CVSS v3 base score is 6.3 out of 10.