CVE-2026-61911

MEDIUM CVSS 3.1: 4.3 EPSS 0.22%
Updated Sep 09, 2026
Cyrusimap
Parameter Value
CVSS 4.3 (MEDIUM)
Affected Versions 3.11.0 — 3.8.8
Fixed In 3.8.8
Type CWE-497
Vendor Cyrusimap
Public PoC No

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.

Attack Parameters

Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Privileges Required
Low
Basic privileges needed
User Interaction
None
No user interaction needed

Impact Assessment

Confidentiality
Low
Partial data leak
Integrity
None
No data modification
Availability
None
No disruption

CVSS Vector v3.1

Weakness Type (CWE)

Vulnerable Products 3

Configuration From (including) Up to (excluding)
Cyrusimap Cyrus_Imap
cpe:2.3:a:cyrusimap:cyrus_imap:*:*:*:*:*:*:*:*
3.8.8
Cyrusimap Cyrus_Imap
cpe:2.3:a:cyrusimap:cyrus_imap:*:*:*:*:*:*:*:*
3.9.0 3.10.4
Cyrusimap Cyrus_Imap
cpe:2.3:a:cyrusimap:cyrus_imap:*:*:*:*:*:*:*:*
3.11.0 3.12.4