Double Free in Cyrus Imap
CVE-2026-61915
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.
Vulnerability class: Double Free
Published · last modified .
CVSS v3 metric
CVSS v3 base score 4.2 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:L.
EPSS exploit prediction
EPSS: 0.003 (16.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 17th percentile — 16.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.003 · change: -0.002
Affected products
Weakness classification (CWE)
References
- cyrusimap.org (Product)
- www.cyrusimap.org/3.12/imap/download/release-notes/3.10/x/3.10.4.html (Release Notes)
- www.cyrusimap.org/3.12/imap/download/release-notes/3.12/x/3.12.4.html (Release Notes)
- www.cyrusimap.org/3.12/imap/download/release-notes/3.8/x/3.8.8.html (Release Notes)
Frequently asked questions
- What is CVE-2026-61915?
- CVE-2026-61915 is a medium-severity vulnerability in Cyrus Imap, classified under Double Free. CVSS score: 4.2/10. Published 2026-09-09.
- How severe is CVE-2026-61915?
- Medium severity. CVSS v3 base score is 4.2 out of 10.