Dovecot SQL based authentication can be bypassed when auth_username_chars is cleared by admin. This vulnerability allows bypassing authentication for any user and user enumeration. Do not clear auth_username_chars. If this is not possible, install latest fixed version. No publicly available exploits are known.
Fix
Public exploits 1
- aramosf/CVE-2026-24031 PoC on GitHub
Each line links to the index that lists it, never to exploit code. Exploit-DB's "verified" and a Metasploit rank of good or better count as verified; a PoC-in-GitHub entry is a repository's claim.
Patch, vendor advisory and mitigation references on NVD 1
- https://documentation.open-xchange.com/dovecot/security/advisories/csaf/2026/oxdc-adv-2026-0001.json Vendor Advisory
Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.
Change history 1
- First seenCVSS 8.2 · dovecot, open-xchangeNVD modified 2026-10-26 21:10
Affected (CPE criteria) 2
cpe:2.3:a:dovecot:dovecot:*:*:*:*:*:*:*:*cpe:2.3:a:open-xchange:dovecot:*:*:*:*:pro:*:*:*