CVE-2026-61911
Published:September 09, 2026
Updated:September 22, 2026
An issue was discovered in Cyrus IMAP before 3.12.4. There is a Sieve mailbox existence oracle. An authenticated user could install a Sieve script that probed whether another user's private mailbox existed, or read the value of shared mailbox annotations, by observing which fileinto branch fired during LMTP delivery.
Affected Packages
https://github.com/cyrusimap/cyrus-imapd.git (GITHUB):
Affected version(s) >=cyrus-imapd-3.7.0-alpha0 <cyrus-imapd-3.8.8Fix Suggestion:
Update to version cyrus-imapd-3.8.8https://github.com/cyrusimap/cyrus-imapd.git (GITHUB):
Affected version(s) >=cyrus-imapd-3.9.0-alpha0 <cyrus-imapd-3.10.4Fix Suggestion:
Update to version cyrus-imapd-3.10.4https://github.com/cyrusimap/cyrus-imapd.git (GITHUB):
Affected version(s) >=cyrus-imapd-3.11.0-alpha0 <cyrus-imapd-3.12.4Fix Suggestion:
Update to version cyrus-imapd-3.12.4Related Resources (4)
Do you need more information?
Contact UsCVSS v4
Base Score:
5.3
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
LOW
User Interaction
NONE
Vulnerable System Confidentiality
LOW
Vulnerable System Integrity
NONE
Vulnerable System Availability
NONE
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
4.3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
LOW
Integrity
NONE
Availability
NONE
Weakness Type (CWE)
Exposure of Sensitive System Information to an Unauthorized Control Sphere
EPSS
Base Score:
0.22