CVE-2026-54369: acl < 2.4.0 Symlink Traversal Privilege Escalation via libacl Functions

Severity: high (CVSS 7.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-06-29 · updated 2026-10-25
Weakness: CWE-59

Description

acl before version 2.4.0 contains a symlink traversal vulnerability in the libacl pathname-based functions acl_get_file(), acl_set_file(), acl_extended_file(), and acl_delete_def_file() that allows local attackers to escalate privileges by replacing any pathname component with a symbolic link. Attackers who control any component of a pathname processed by a privileged caller can redirect ACL read or write operations to arbitrary files or directories, enabling unauthorized manipulation of access control lists and local privilege escalation.

Affected products

acl project acl: before 2.4.0 — fixed in 2.4.0

How to fix

Upgrade to a fixed version: acl project acl 2.4.0. Check the vendor advisory for mitigations.

References

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