CVE-2026-61909
published 2026-09-09CVE-2026-61909: 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…
PriorityP422medium4.3CVSS 3.1
AVNACLPRLUINSUCLINAN
EPSS
0.20%
10.3th percentile
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.
Affected
7 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| cyrus | imap | < 3.8.8 | 3.8.8 |
| cyrus | imap | >= 3.11.0 < 3.12.4 | 3.12.4 |
| cyrus | imap | >= 3.9.0 < 3.10.4 | 3.10.4 |
| cyrusimap | cyrus_imap | < 3.8.8 | 3.8.8 |
| cyrusimap | cyrus_imap | >= 3.11.0 < 3.12.4 | 3.12.4 |
| cyrusimap | cyrus_imap | >= 3.9.0 < 3.10.4 | 3.10.4 |
| debian | cyrus-imapd | — | — |
CVSS provenance
nvdv3.14.3MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
vendor_redhat3.5LOW
Stop checking back — get the weekly exploitation signal.
Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.
VulDB
Cyrus IMAP up to 3.8.7/3.10.3/3.12.3 CalDAV/CardDAV information disclosure
vuldb·2026-09-09·CVSS 3.5
CVE-2026-61909 [LOW] Cyrus IMAP up to 3.8.7/3.10.3/3.12.3 CalDAV/CardDAV information disclosure
A vulnerability classified as problematic has been found in Cyrus IMAP up to 3.8.7/3.10.3/3.12.3. The affected element is an unknown function of the component CalDAV/CardDAV. This manipulation causes information disclosure.
The identification of this vulnerability is CVE-2026-61909. It is possible to initiate the attack remotely. There is no exploit available.
It is recommended to upgrade the affected component.
GHSA
An issue was discovered in Cyrus IMAP before 3.12.4.
ghsa_unreviewed·2026-09-09
CVE-2026-61909 [LOW] CWE-420 An issue was discovered in Cyrus IMAP before 3.12.4.
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.
Red Hat
cyrus-imapd: cyrus-imapd: CalDAV/CardDAV multiget bypasses per-href ACL
vendor_redhat·2026-09-10·CVSS 3.5
CVE-2026-61909 [LOW] CWE-420 cyrus-imapd: cyrus-imapd: CalDAV/CardDAV multiget bypasses per-href ACL
cyrus-imapd: cyrus-imapd: CalDAV/CardDAV multiget bypasses per-href ACL
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.
A flaw was found in cyrus-imapd. An authenticated DAV (Distributed Authoring and Versioning) user with some shared access to another user's calendar or address book could read unshared events or contacts. This information disclosure occurs by including specific resource identifiers in a calendar-multiget or addressbook-multiget REPORT, bypassing intended access controls.
Mitigation: To reduce the a
No detection rules found.
No public exploits indexed.
Bugzilla
CVE-2026-61909 cyrus-imapd: cyrus-imapd: CalDAV/CardDAV multiget bypasses per-href ACL [fedora-all]
bugzilla·2026-09-10·CVSS 3.5
CVE-2026-61909 [LOW] CVE-2026-61909 cyrus-imapd: cyrus-imapd: CalDAV/CardDAV multiget bypasses per-href ACL [fedora-all]
CVE-2026-61909 cyrus-imapd: cyrus-imapd: CalDAV/CardDAV multiget bypasses per-href ACL [fedora-all]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
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.
Bugzilla
CVE-2026-61909 cyrus-imapd: cyrus-imapd: CalDAV/CardDAV multiget bypasses per-href ACL
bugzilla·2026-08-31·CVSS 3.5
CVE-2026-61909 [LOW] CVE-2026-61909 cyrus-imapd: cyrus-imapd: CalDAV/CardDAV multiget bypasses per-href ACL
CVE-2026-61909 cyrus-imapd: cyrus-imapd: CalDAV/CardDAV multiget bypasses 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.
2026-09-09
Published