CVE-2024-52805: Matrix Synapse

High severity, CVSS 7.5. EPSS: 0.7% chance of exploitation in the next 30 days.

Synapse is an open-source Matrix homeserver. In Synapse before 1.120.1, multipart/form-data requests can in certain configurations transiently increase memory consumption beyond expected levels while processing the request, which can be used to amplify denial of service attacks. Synapse 1.120.1 resolves the issue by denying requests with unsupported multipart/form-data content type.

Affected products

• Matrix Synapse: before 1.120.1 (fixed in 1.120.1)

Published 2024-12-03. Last modified 2026-06-17.