{"cve":"CVE-2024-37303","nvd":{"published":"2024-12-03T17:15:10.890","modified":"2026-06-17T07:38:06.270","status":"Analyzed","description":"Synapse is an open-source Matrix homeserver. Synapse before version 1.106 allows, by design, unauthenticated remote participants to trigger a download and caching of remote media from a remote homeserver to the local media repository. Such content then also becomes available for download from the local homeserver in an unauthenticated way. The implication is that unauthenticated remote adversaries can use this functionality to plant problematic content into the media repository. Synapse 1.106 introduces a partial mitigation in the form of new endpoints which require authentication for media downloads. The unauthenticated endpoints will be frozen in a future release, closing the attack vector.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N","score":5.3},"cwes":["CWE-306"],"references":["https://github.com/element-hq/synapse/security/advisories/GHSA-gjgr-7834-rhxr","https://github.com/matrix-org/matrix-spec-proposals/pull/3916"],"products":["matrix:synapse"],"source":"nvd","synced_at":"2026-10-19T21:57:36.180738747+00:00"},"epss":{"cve":"CVE-2024-37303","score":0.0043,"percentile":0.37284,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-gjgr-7834-rhxr","url":"https://osv.dev/vulnerability/GHSA-gjgr-7834-rhxr","summary":"Synapse's unauthenticated writes to the media repository allow planting of problematic content","modified":"2026-06-06T00:45:45.835783438Z","packages":[{"ecosystem":"PyPI","name":"matrix-synapse","purl":"pkg:pypi/matrix-synapse","ranges":["<1.106"],"fixed":["1.106"]}]},{"id":"PYSEC-2024-287","url":"https://osv.dev/vulnerability/PYSEC-2024-287","summary":"","modified":"2026-05-20T09:19:06.870905Z","packages":[{"ecosystem":"PyPI","name":"matrix-synapse","purl":"pkg:pypi/matrix-synapse","ranges":["<1.106.0"],"fixed":["1.106.0"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}