Matrix Synapse

40 CVEs affecting Matrix Synapse. Latest disclosed: 2025-03-27. Critical: 2, High: 11.

Top CVEs affecting Matrix Synapse
CVESeverityScorePublishedSummary
CVE-2019-18835Critical9.82019-11-08Matrix Synapse before 1.5.0 mishandles signature checking on some federation APIs. Events sent over /send_join, /send_leave, and /invite may not be correctly s…
CVE-2024-53863Critical9.12024-12-03Synapse is an open-source Matrix homeserver. In Synapse versions before 1.120.1, enabling the dynamic_thumbnails option or processing a specially crafted reque…
CVE-2018-16515High8.82018-09-18Matrix Synapse before 0.33.3.1 allows remote attackers to spoof events and possibly have unspecified other impacts by leveraging improper transaction and event…
CVE-2024-52805High7.52024-12-03Synapse is an open-source Matrix homeserver. In Synapse before 1.120.1, multipart/form-data requests can in certain configurations transiently increase memory…
CVE-2024-37302High7.52024-12-03Synapse is an open-source Matrix homeserver. Synapse versions before 1.106 are vulnerable to a disk fill attack, where an unauthenticated adversary can induce…
CVE-2021-41281High7.52021-11-23Synapse is a package for Matrix homeservers written in Python 3/Twisted. Prior to version 1.47.1, Synapse instances with the media repository enabled can be tr…
CVE-2020-26890High7.52020-11-24Matrix Synapse before 1.20.0 erroneously permits non-standard NaN, Infinity, and -Infinity JSON values in fields of m.room.member events, allowing remote attac…
CVE-2019-11842High7.52019-05-09An issue was discovered in Matrix Sydent before 1.0.3 and Synapse before 0.99.3.1. Random number generation is mishandled, which makes it easier for attackers…
CVE-2019-5885High7.52019-03-21Matrix Synapse before 0.34.0.1, when the macaroon_secret_key authentication parameter is not set, uses a predictable value to derive a secret key and other sec…
CVE-2018-12423High7.52018-06-14In Synapse before 0.31.2, unauthorised users can hijack rooms when there is no m.room.power_levels event in force.
CVE-2018-12291High7.52018-06-13The on_get_missing_events function in handlers/federation.py in Matrix Synapse before 0.31.1 has a security bug in the get_missing_events federation API where…
CVE-2018-10657High7.52018-05-02Matrix 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 feder…
CVE-2025-30355High7.12025-03-27Synapse is an open source Matrix homeserver implementation. A malicious server can craft events which, when received, prevent Synapse version up to 1.127.0 fro…
CVE-2021-21332Medium6.92021-03-26Synapse is a Matrix reference homeserver written in python (pypi package matrix-synapse). Matrix is an ecosystem for open federated Instant Messaging and VoIP…
CVE-2024-31208Medium6.52024-04-23Synapse is an open-source Matrix homeserver. A remote Matrix user with malicious intent, sharing a room with Synapse instances before 1.105.1, can dispatch spe…
CVE-2022-39374Medium6.52023-05-26Synapse is an open-source Matrix homeserver written and maintained by the Matrix.org Foundation. If Synapse and a malicious homeserver are both joined to the s…
CVE-2022-41952Medium6.52022-11-22Synapse before 1.52.0 with URL preview functionality enabled will attempt to generate URL previews for media stream URLs without properly limiting connection t…
CVE-2022-31052Medium6.52022-06-28Synapse is an open source home server implementation for the Matrix chat network. In versions prior to 1.61.1 URL previews of some web pages can exhaust the av…
CVE-2020-26257Medium6.52020-12-09Matrix is an ecosystem for open federated Instant Messaging and VoIP. Synapse is a reference "homeserver" implementation of Matrix. A malicious or poorly-imple…
CVE-2022-31152Medium6.42022-09-02Synapse is an open-source Matrix homeserver written and maintained by the Matrix.org Foundation. The Matrix specification specifies a list of [event authorizat…