CVE-2026-27860

A flaw was found in Dovecot. A remote attacker could exploit this vulnerability by injecting malicious Lightweight Directory Access Protocol LDAP filters during the authentication process. This is possible if the authusernamechars configuration setting is empty. Successful exploitation could allo...

ALPINE-CVE-2026-27860

If authusernamechars is empty, it is possible to inject arbitrary LDAP filter to Dovecot's LDAP authentication. This leads to potentially bypassing restrictions and allows probing of LDAP structure. Do not clear out authusernamechars, or install fixed version. No publicly available exploits are...