CVE-2025-30355 – matrix-synapse

Package

Manager: pip
Name: matrix-synapse
Vulnerable Version: >=0 <1.127.1

Severity

Level: High

CVSS v3.1: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H

CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N

EPSS: 0.05781 pctl0.90131

Details

Synapse vulnerable to federation denial of service via malformed events ### Impact A malicious server can craft events which, when received, prevent Synapse version up to 1.127.0 from federating with other servers. The vulnerability has been exploited in the wild. ### Patches Fixed in Synapse v1.127.1. ### Workarounds Closed federation environments of trusted servers or non-federating installations are not affected. ### For more information If you have any questions or comments about this advisory, please email us at [security at element.io](mailto:security@element.io).

Metadata

Created: 2025-03-27T18:02:14Z
Modified: 2025-03-27T18:02:14Z
Source: https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2025/03/GHSA-v56r-hwv5-mxg6/GHSA-v56r-hwv5-mxg6.json
CWE IDs: ["CWE-20"]
Alternative ID: GHSA-v56r-hwv5-mxg6
Finding: F184
Auto approve: 1