Memory Exhaustion Vulnerability in Stalwart Mail and Collaboration Server

CVE-2025-59045

What is CVE-2025-59045?

A memory exhaustion flaw has been identified in Stalwart's CalDAV implementation, affecting versions prior to 0.13.3. This vulnerability allows authenticated users to exploit the system by creating recurring events with extensive payloads, causing excessive memory consumption and potentially leading to a denial-of-service condition. When the server receives requests to expand these events, it fails to enforce limits on memory allocation, which can result in significant usage spikes. It is crucial for users on affected versions to upgrade to 0.13.3 or implement mitigation strategies, such as memory limits and rate limiting for CalDAV requests, to secure the server.

References