Synapse 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 specially crafted events to exploit a weakness in the V2 state resolution algorithm. This can induce high CPU consumption and accumulate excessive data in the database of such instances, resulting in a denial of service. Servers in private federations, or those that do not federate, are not affected. Server administrators should upgrade to 1.105.1 or later. Some workarounds are available. One can ban the malicious users or ACL block servers from the rooms and/or leave the room and purge the room using the admin API.
Metrics
Affected Vendors & Products
References
History
Tue, 26 Aug 2025 19:00:00 +0000
Type | Values Removed | Values Added |
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First Time appeared |
Fedoraproject
Fedoraproject fedora Matrix Matrix synapse |
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CPEs | cpe:2.3:a:matrix:synapse:*:*:*:*:*:*:*:* cpe:2.3:o:fedoraproject:fedora:38:*:*:*:*:*:*:* cpe:2.3:o:fedoraproject:fedora:39:*:*:*:*:*:*:* cpe:2.3:o:fedoraproject:fedora:40:*:*:*:*:*:*:* |
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Vendors & Products |
Fedoraproject
Fedoraproject fedora Matrix Matrix synapse |

Status: PUBLISHED
Assigner: GitHub_M
Published:
Updated: 2025-02-13T17:47:51.943Z
Reserved: 2024-03-29T14:16:31.900Z
Link: CVE-2024-31208

Updated: 2024-04-23T19:12:21.539Z

Status : Analyzed
Published: 2024-04-23T18:15:14.457
Modified: 2025-08-26T18:45:47.210
Link: CVE-2024-31208

No data.

Updated: 2025-07-12T22:23:16Z