CVE-2026-0394: dovecot Path Traversal

Vulnerability summary

CVE-2026-0394 is a medium (CVSS 5.3) Path Traversal vulnerability in dovecot. EPSS estimates a 0.43% chance of exploitation in the next 30 days, higher than 35.6% of scored vulnerabilities.

Timeline

1. 27-03-2026
   PublishedVulnerability first disclosed.
2. 27-03-2026
   Last modifiedVulnerability information updated.

Description

When dovecot has been configured to use per-domain passwd files, and they are placed one path component above /etc, or slash has been added to allowed characters, path traversal can happen if the domain component is directory partial. This allows inadvertently reading /etc/passwd (or some other path which ends with passwd). If this file contains passwords, it can be used to authenticate wrongly, or if this is userdb, it can unexpectly make system users appear valid users. Upgrade to fixed version, or use different authentication scheme that does not rely on paths. Alternatively you can also ensure that the per-domain passwd files are in some other location, such as /etc/dovecot/auth/%d. No publicly available exploits are known.

• CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.