CVE-2025-30355

HIGH EPSS 63.1%
Published Mar 27, 20251y ago · Modified Jun 17, 20262w ago
7.5 CVSS 3.1
High
Find Similar
Published Mar 27, 2025 1y ago
Last Modified Jun 17, 2026 2w ago

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.

CVSS Details

Base Score
7.5
Exploitability
3.9
Impact
3.6
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality None
Integrity None
Availability High

Threat Intelligence

EPSS Exploit Probability
63.1% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 1

CWE-20 Improper Input Validation Validation

Affected Products 1

VendorProductVersionRange
matrixsynapse* <1.127.1

References 3

  • github.com https://github.com/element-hq/synapse/commit/2277df2a1eb685f85040ef98fa21d41aa4cdd389
    Patch
  • github.com https://github.com/element-hq/synapse/releases/tag/v1.127.1
    Release Notes
  • github.com https://github.com/element-hq/synapse/security/advisories/GHSA-v56r-hwv5-mxg6
    Vendor Advisory

Remediation

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