{"id":"CVE-2024-52805","aliases":["GHSA-rfq8-j7rh-8hf2","PYSEC-2026-1613"],"url":"https://o3.security/vulnerability/CVE-2024-52805","summary":"Synapse allows unsupported content types to lead to memory exhaustion","details":"### Impact\n\nIn 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.\n\n### Patches\n\nSynapse 1.120.1 resolves the issue by denying requests with unsupported `multipart/form-data` content type.\n\n### Workarounds\n\nLimiting 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.\n\n### References\n\n- https://github.com/twisted/twisted/issues/4688#issuecomment-1167705518\n- https://github.com/twisted/twisted/issues/4688#issuecomment-2385711609\n\n### For more information\n\nIf you have any questions or comments about this advisory, please email us at [security at element.io](mailto:security@element.io).\n","published":"2024-12-03T17:01:50.119Z","modified":"2026-08-12T03:51:45.989508767Z","cvss":null,"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"PyPI","name":"matrix-synapse","fixedVersion":"1.120.1"}],"fix":null,"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/52xxx/CVE-2024-52805.json"},{"type":"ADVISORY","url":"https://github.com/element-hq/synapse/security/advisories/GHSA-rfq8-j7rh-8hf2"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2024-52805"},{"type":"REPORT","url":"https://github.com/twisted/twisted/issues/4688#issuecomment-1167705518"},{"type":"REPORT","url":"https://github.com/twisted/twisted/issues/4688#issuecomment-2385711609"},{"type":"PACKAGE","url":"https://github.com/element-hq/synapse"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:45.989508767Z"}}