https://cve.radiocsirt.org/rss/recent/all/10 Most recent entries from all 2026-10-03T20:05:49.228267+00:00 Vulnerability-Lookup csirt@opendfir.org python-feedgen Contains only the most 10 recent entries. https://cve.radiocsirt.org/vuln/cve-2024-52805 CVE-2024-52805 — Synapse allows unsupported content types to lead to memory exhaustion 2026-10-03T20:05:49.230122+00:00

Affected: element-hq synapse

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.

 https://cve.radiocsirt.org/vuln/ghsa-rfq8-j7rh-8hf2 GHSA-rfq8-j7rh-8hf2 — Synapse allows unsupported content types to lead to memory exhaustion 2026-10-03T20:05:49.230188+00:00

Affected: PyPI: matrix-synapse

### Impact

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.

### Patches

Synapse 1.120.1 resolves the issue by denying requests with unsupported `multipart/form-data` content type.

### Workarounds

Limiting request sizes or blocking the `multipart/form-data` content type before the requests reach Synapse, for example in a reverse proxy, alleviates the issue. Another approach that mitigates the attack is to use a low `max_upload_size` in Synapse.

### References

- https://github.com/twisted/twisted/issues/4688#issuecomment-1167705518 - https://github.com/twisted/twisted/issues/4688#issuecomment-2385711609

### For more information

If you have any questions or comments about this advisory, please email us at [security at element.io](mailto:security@element.io).