CVE-2026-61915

A flaw was found in cyrus-imapd. An authenticated calendar user could trigger a double-free vulnerability in the Cyrus CalDAV worker. By sending a specially crafted PATCH request that includes PATCH-ACTION="BYPARAM@..." against a resource with two or more properties of the matched kind, the memory holding the selector would be freed multiple times. This could lead to a denial of service by crashing the CalDAV worker.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.