{"cve":"CVE-2024-37302","nvd":{"published":"2024-12-03T17:15:10.733","modified":"2026-06-17T07:38:06.163","status":"Analyzed","description":"Synapse is an open-source Matrix homeserver. Synapse versions before 1.106 are vulnerable to a disk fill attack, where an unauthenticated adversary can induce Synapse to download and cache large amounts of remote media. The default rate limit strategy is insufficient to mitigate this. This can lead to a denial of service, ranging from further media uploads/downloads failing to completely unavailability of the Synapse process, depending on how Synapse was deployed. Synapse 1.106 introduces a new \"leaky bucket\" rate limit on remote media downloads to reduce the amount of data a user can request at a time. This does not fully address the issue, but does limit an unauthenticated user's ability to request large amounts of data to be cached.","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:N/A:H","score":7.5},"cwes":["CWE-770"],"references":["https://github.com/element-hq/synapse/security/advisories/GHSA-4mhg-xv73-xq2x"],"products":["matrix:synapse"],"source":"nvd","synced_at":"2026-10-19T21:57:36.180738747+00:00"},"epss":{"cve":"CVE-2024-37302","score":0.00596,"percentile":0.48498,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-4mhg-xv73-xq2x","url":"https://osv.dev/vulnerability/GHSA-4mhg-xv73-xq2x","summary":"Synapse denial of service through media disk space consumption","modified":"2026-06-06T00:45:50.309167032Z","packages":[{"ecosystem":"PyPI","name":"matrix-synapse","purl":"pkg:pypi/matrix-synapse","ranges":["<1.106"],"fixed":["1.106"]}]},{"id":"PYSEC-2024-286","url":"https://osv.dev/vulnerability/PYSEC-2024-286","summary":"","modified":"2026-05-20T09:19:06.777355Z","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."]}