{"schemaVersion":3,"id":"CVE-2020-26890","aliases":["GHSA-4mp3-385r-v63f","PYSEC-2020-237","UBUNTU-CVE-2020-26890","DEBIAN-CVE-2020-26890"],"status":"published","duplicateOf":null,"title":null,"description":"Matrix Synapse before 1.20.0 erroneously permits non-standard NaN, Infinity, and -Infinity JSON values in fields of m.room.member events, allowing remote attackers to execute a denial of service attack against the federation and common Matrix clients. If such a malformed event is accepted into the room's state, the impact is long-lasting and is not fixed by an upgrade to a newer version, requiring the event to be manually redacted instead. 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