CVE-2026-54369
Description
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.
Statement
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.
Mitigation
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.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.1 | N/A | 7.1 |
| Attack Vector | Local | N/A | Local |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | Low | N/A | Low |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | High |
| Integrity Impact | High | N/A | High |
| Availability Impact | None | N/A | None |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
cve.org: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
Understanding the Weakness (CWE)
Confidentiality,Integrity,Access Control
Technical Impact: Read Files or Directories; Modify Files or Directories; Bypass Protection Mechanism
An attacker may be able to traverse the file system to unintended locations and read or overwrite the contents of unexpected files. If the files are used for a security mechanism then an attacker may be able to bypass the mechanism.
Other
Technical Impact: Execute Unauthorized Code or Commands
Windows simple shortcuts, sometimes referred to as soft links, can be exploited remotely since a ".LNK" file can be uploaded like a normal file. This can enable remote execution.
Acknowledgements
Red Hat would like to thank Alexander Peslyak <solar@openwall.com> and Andrew Tridgell <tridge60@gmail.com> for reporting this issue.
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