High severity · published Sep 9, 2026
CVE-2026-61915
An issue was discovered in Cyrus IMAP before 3.12.4
7.1
CVSS
0.3%
EPSS
No
On KEV
Description
An issue was discovered in Cyrus IMAP before 3.12.4. There is a VPATCH BYPARAM double-free. An authenticated calendar user could crash a Cyrus CalDAV worker with a PATCH containing PATCH-ACTION="BYPARAM@..." against a resource with two or more properties of the matched kind. The memory holding the selector would be freed once on each iteration over the properties.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
None
Integrity
Low
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 17% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
CI
Cyrus IMAP · cyrusimap
before 3.8.8; 3.9.0 before 3.10.4; 3.11.0 before 3.12.4 · source: vendor
IM
Imap · Cyrus
before 3.8.8; 3.9.0 before 3.10.4; 3.11.0 before 3.12.4 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-61915
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-61915
Product
https://cyrusimap.org
Release Notes
https://www.cyrusimap.org/3.12/imap/download/release-notes/3.10/x/3.10.4.html
Release Notes
https://www.cyrusimap.org/3.12/imap/download/release-notes/3.12/x/3.12.4.html
Release Notes
https://www.cyrusimap.org/3.12/imap/download/release-notes/3.8/x/3.8.8.html
More from Cyrus IMAP
6.5
CVE-2026-61908
An issue was discovered in Cyrus IMAP before 3.12.4
6.5
CVE-2026-47084
An issue was discovered in cyrus-imapd in Cyrus IMAP through 3.12.2
6.5
CVE-2024-34055
Cyrus IMAP before 3.8.3 and 3.10.x before 3.10.0-rc1 allows authenticated attackers to cause unbounded memory allocation by sending many LITERALs in a single command
6.5
CVE-2017-12843
Cyrus IMAP before 3.0.3 allows remote authenticated users to write to arbitrary files via a crafted (1) SYNCAPPLY, (2) SYNCGET or (3) SYNCRESTORE command
5.4
CVE-2026-47082
An issue was discovered in cyrus-imapd in Cyrus IMAP through 3.12.2