{"cve":"CVE-2018-10657","nvd":{"published":"2018-05-02T16:29:00.233","modified":"2026-06-17T01:34:23.473","status":"Modified","description":"Matrix Synapse before 0.28.1 is prone to a denial of service flaw where malicious events injected with depth = 2^63 - 1 render rooms unusable, related to federation/federation_base.py and handlers/message.py, as exploited in the wild in April 2018.","cvss_v4":null,"cvss_v3":{"version":"3.0","vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":7.5},"cwes":["CWE-20"],"references":["https://github.com/matrix-org/synapse/commit/33f469ba19586bbafa0cf2c7d7c35463bdab87eb","https://matrix.org/blog/2018/05/01/security-update-synapse-0-28-1/","https://github.com/matrix-org/synapse/commit/33f469ba19586bbafa0cf2c7d7c35463bdab87eb","https://matrix.org/blog/2018/05/01/security-update-synapse-0-28-1/"],"products":["matrix:synapse"],"source":"nvd","synced_at":"2026-10-19T20:50:40.212176939+00:00"},"epss":{"cve":"CVE-2018-10657","score":0.01494,"percentile":0.74158,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-vmcc-4p4x-x7wg","url":"https://osv.dev/vulnerability/GHSA-vmcc-4p4x-x7wg","summary":"Matrix Synapse DoS","modified":"2026-07-07T11:56:12.318339049Z","packages":[{"ecosystem":"PyPI","name":"matrix-synapse","purl":"pkg:pypi/matrix-synapse","ranges":["<0.28.1"],"fixed":["0.28.1"]}]},{"id":"PYSEC-2026-846","url":"https://osv.dev/vulnerability/PYSEC-2026-846","summary":"Matrix Synapse DoS","modified":"2026-07-07T11:46:05.957211927Z","packages":[{"ecosystem":"PyPI","name":"matrix-synapse","purl":"pkg:pypi/matrix-synapse","ranges":["<0.28.1"],"fixed":["0.28.1"]}]}],"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."]}