CVE-2026-61911 | BDVDB-2026-370608 Detail

cyrusimapCyrus IMAP

Description#

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.

Impact#

Per CVSS v3.1: confidentiality impact low, integrity impact none, availability impact none. Attack vector: network.

Weaknesses#

CWE-497 Exposure of Sensitive System Information to an Unauthorized Control Sphere

References#

Exploit#

No public exploit known

History#

Version 12026-09-09Record published in the CVE List.
Version 22026-09-10Most recent update recorded in the CVE List.

Published

Published: 2026-09-09
Last modified: 2026-09-10

Vendor information

Vendor: cyrusimap
Product: Cyrus IMAP

All cyrusimap vulnerabilities

Score

4.3 Medium

EPSS

less than 1%, Very Low

Estimated chance of exploitation in the next 30 days. EPSS percentile: 12.3.

KEV

Not listed in the CISA Known Exploited Vulnerabilities catalog.

Impact

Not classified

Action

No specific action is recorded in the source data. Check the references for vendor guidance.

Affected Systems

Vulnerable
< 3.8.8
Fixed
3.8.8
Vulnerable
>= 3.9.0 and < 3.10.4
Fixed
3.10.4
Vulnerable
>= 3.11.0 and < 3.12.4
Fixed
3.12.4

Scoring System

CVSS v4.0

Not available

CVSS v3.1

4.3 Medium

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

Metric breakdown
Attack Vector	Network
Attack Complexity	Low
Privileges Required	Low
User Interaction	None
Scope	Unchanged
Confidentiality	Low
Integrity	None
Availability	None

CVSS v3.0

Not available

CVSS v2

Not available

Source: CVE List v5 (record); CISA KEV (kev, action); FIRST EPSS (epss).