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.
History

Tue, 26 Aug 2025 19:00:00 +0000

Type Values Removed Values Added
First Time appeared Fedoraproject
Fedoraproject fedora
Matrix
Matrix synapse
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:*:*:*:*:*:*:*
Vendors & Products Fedoraproject
Fedoraproject fedora
Matrix
Matrix synapse

cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2025-02-13T17:47:51.943Z

Reserved: 2024-03-29T14:16:31.900Z

Link: CVE-2024-31208

cve-icon Vulnrichment

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

cve-icon NVD

Status : Analyzed

Published: 2024-04-23T18:15:14.457

Modified: 2025-08-26T18:45:47.210

Link: CVE-2024-31208

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

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