VDB
CVE-2026-27855
CVE-2026-27855
PUBLISHED
CVSS 6.800000190734863 MEDIUM
Dovecot OTP authentication is vulnerable to replay attack under specific conditions. If auth cache is enabled, and username is altered in passdb, then OTP credentials can be cached so that same OTP reply is valid. An attacker able to observe an OTP exchange is able to log in as the user. If authentication happens over unsecure connection, switch to SCRAM protocol. Alternatively ensure the communcations are secured, and if possible switch to OAUTH2 or SCRAM. No publicly available exploits are known.
EPSS 0.04% · 13.1th percentile
Risk Scores
CVSS 3.1
6.800000190734863
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N
EPSS Score
0.04%
13.1th percentile
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Open-Xchange GmbH | OX Dovecot Pro | 0, 0, 0 |
| open-xchange | dovecot | 0 |
| dovecot | dovecot | 0 |
Exploit Intelligence
Timeline
- Mar 27, 2026 Coalition ESS Score
- Mar 27, 2026 CVE Published
- Mar 27, 2026 PoC Published
- Mar 29, 2026 Security Advisory
- Apr 29, 2026 CVE Updated
- May 18, 2026 EPSS Score
- May 19, 2026 EPSS Score
- May 20, 2026 EPSS Score
- May 21, 2026 EPSS Score
- May 22, 2026 EPSS Score
- May 23, 2026 EPSS Score
- May 24, 2026 EPSS Score