CVE-2025-30355

Published: Mar 27, 2025Modified: Jun 17, 2026

7.5

Vector

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

Exploitability: 3.9 / Impact: 3.6

Source: NVD

Description

Synapse is an open source Matrix homeserver implementation. 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 and has been fixed in Synapse v1.127.1. No known workarounds are available.

Affected (1)

Products: Matrix: Synapse

1 product

Configuration A

1 vulnerable

Vulnerable Software	Affected Versions
Matrix Synapse	Before 1.127.1

Related CWEs

Improper Input Validation

The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.

References (3)

https://github.com/element-hq/synapse/commit/2277df2a1eb685f85040ef98fa21d41aa4cdd389

Source: security-advisories@github.com

Patch

https://github.com/element-hq/synapse/releases/tag/v1.127.1

Source: security-advisories@github.com

Release Notes

https://github.com/element-hq/synapse/security/advisories/GHSA-v56r-hwv5-mxg6

Source: security-advisories@github.com

Vendor Advisory

Timeline

No history available yet.