CVE-2026-54369

A flaw was found in the acl package, specifically within its libacl pathname-based functions. A local attacker could exploit this vulnerability by using a symbolic link to replace a pathname component. This could allow the attacker to redirect access control list (ACL) read or write operations to arbitrary files or directories, leading to unauthorized manipulation of ACLs and ultimately local privilege escalation.

Red Hat rates this flaw as Important because a local attacker who controls any component of a pathname processed by a privileged process using libacl can redirect ACL operations to arbitrary files. Exploitation requires local access with the ability to create symlinks in a directory that a privileged program later processes with acl_get_file() or acl_set_file(). In default RHEL and OpenShift CoreOS configurations, standard file permission settings limit where unprivileged users can create symlinks, reducing the practical attack surface. Programs that operate on user-supplied paths with elevated privileges are most at risk.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Restrict unprivileged users from creating symlinks in directories that privileged processes operate on with ACL commands. Where possible, use the fs.protected_symlinks sysctl (enabled by default on RHEL 7+), which prevents symlink following in world-writable sticky directories unless the owner of the symlink matches the owner of the target file or directory.