CVE-2025-30355

Publication date 27 March 2025

Last updated 11 July 2025

Ubuntu priority

Cvss 3 Severity Score

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.

Status

Show unmaintained releases

Package	Ubuntu Release	Status
matrix-synapse	24.10 oracular	Ignored end of life, was needs-triage
	24.04 LTS noble	Needs evaluation
	22.04 LTS jammy	Needs evaluation
	20.04 LTS focal	Needs evaluation
	18.04 LTS bionic	Needs evaluation

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package	Patch details
matrix-synapse	Upstream: 2277df2

Severity score breakdown

Parameter	Value
Base score	7.1 · High
Attack vector	Network
Attack complexity	Low
Privileges required	Low
User interaction	None
Scope	Unchanged
Confidentiality	None
Integrity impact	Low
Availability impact	High
Vector	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H