CVE-2026-27855

medium Red Hat
CVSS v3 Base Score
6.8
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N
EPSS Score
0.0%
Exploitation probability in 30 days
Top 89% most likely to be exploited
Attack Characteristics
Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
Required
Confidentiality
High
Integrity
High
Availability
None
Published: March 27, 2026 (48 days ago)
Last Modified: March 27, 2026
Vendor: Red Hat
Source: REDHAT

Description

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.

CWE

CWE-294

Affected Products

Red Hat Enterprise Linux 10Red Hat Enterprise Linux 6Red Hat Enterprise Linux 7Red Hat Enterprise Linux 8Red Hat Enterprise Linux 9

References

🔗 bugzilla.redhat.com 🔗 www.cve.org 🔗 nvd.nist.gov 🔗 documentation.open-xchange.com