An issue was discovered in Cyrus IMAP before 3.12.4. CalDAV/CardDAV multiget bypasses a per-href ACL. An authenticated DAV user with some shared access to another user's calendar or address book could read even unshared events or contacts by including the target hrefs in a calendar-multiget or addressbook-multiget REPORT.
History

Wed, 16 Sep 2026 15:30:00 +0000

Type Values Removed Values Added
First Time appeared Cyrus
Cyrus imap
CPEs cpe:2.3:a:cyrus:imap:*:*:*:*:*:*:*:*
Vendors & Products Cyrus
Cyrus imap

Mon, 14 Sep 2026 21:00:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Thu, 10 Sep 2026 12:15:00 +0000

Type Values Removed Values Added
Title CalDAV/CardDAV Multiget ACL Bypass in Cyrus IMAP cyrus-imapd: cyrus-imapd: CalDAV/CardDAV multiget bypasses per-href ACL
References
Metrics threat_severity

None

threat_severity

Moderate


Wed, 09 Sep 2026 22:30:00 +0000

Type Values Removed Values Added
Title CalDAV/CardDAV Multiget ACL Bypass in Cyrus IMAP

Wed, 09 Sep 2026 20:00:00 +0000

Type Values Removed Values Added
Description An issue was discovered in Cyrus IMAP before 3.12.4. CalDAV/CardDAV multiget bypasses a per-href ACL. An authenticated DAV user with some shared access to another user's calendar or address book could read even unshared events or contacts by including the target hrefs in a calendar-multiget or addressbook-multiget REPORT.
First Time appeared Cyrusimap
Cyrusimap cyrus Imap
Weaknesses CWE-420
CPEs cpe:2.3:a:cyrusimap:cyrus_imap:*:*:*:*:*:*:*:*
Vendors & Products Cyrusimap
Cyrusimap cyrus Imap
References
Metrics cvssV3_1

{'score': 3.5, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:N/A:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: mitre

Published: 2026-09-09T00:00:00.000Z

Updated: 2026-09-14T15:21:10.144Z

Reserved: 2026-07-13T00:00:00.000Z

Link: CVE-2026-61909

cve-icon Vulnrichment

Updated: 2026-09-14T15:21:06.557Z

cve-icon NVD

Status : Analyzed

Published: 2026-09-09T20:18:36.523

Modified: 2026-09-16T15:24:24.070

Link: CVE-2026-61909

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-09-10T07:42:41Z

Links: CVE-2026-61909 - Bugzilla