GHSA-V56R-HWV5-MXG6 Synapse vulnerable to federation denial of service via malformed events

Impact A malicious server can craft events with a depth outside the integer range allowed by Canonical JSON. When such an event is received by Synapse version up to 1.127.0, it prevents it from federating with other servers. The vulnerability has been exploited in the wild. Patches Fixed in Synap...

CVE-2025-30355 Synapse vulnerable to federation denial of service via malformed events

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...

CVE-2025-30355 Synapse vulnerable to federation denial of service via malformed events

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...

py-matrix-synapse -- federation denial of service via malformed events

element-hq/synapse developers report: 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...

Matrix Synapse License Issue Vulnerability

Matrix Synapse is a Matrix Management Server implementation from the Matrix Foundation in the UK. Matrix Synapse suffers from a security vulnerability that stems from the fact that a malicious or poorly implemented host server can inject malformed events by specifying different room ids in the pa...

UBUNTU-CVE-2020-26257

Matrix is an ecosystem for open federated Instant Messaging and VoIP. Synapse is a reference "homeserver" implementation of Matrix. A malicious or poorly-implemented homeserver can inject malformed events into a room by specifying a different room id in the path of a /sendjoin, /sendleave, /invit...

GHSA-HXMP-PQCH-C8MM Denial of service attack via incorrect parameters in Matrix Synapse

Impact A malicious or poorly-implemented homeserver can inject malformed events into a room by specifying a different room id in the path of a /sendjoin, /sendleave, /invite or /exchangethirdpartyinvite request. This can lead to a denial of service in which future events will not be correctly sen...

Matrix Synapse 资源管理错误漏洞

Matrix Synapse is a Matrix Management Server implementation from the Matrix Foundation in the UK. Matrix Synapse suffers from a security vulnerability that stems from the fact that a malicious or poorly implemented host server can inject malformed events by specifying different room ids in the pa...

py-matrix-synapse -- DoS on Federation API

Matrix developers reports: A malicious or poorly-implemented homeserver can inject malformed events into a room by specifying a different room id in the path of a /sendjoin, /sendleave, /invite or /exchangethirdpartyinvite request. This can lead to a denial of service in which future events will...

CVE-2020-26890

Matrix Synapse before 1.20.0 erroneously permits non-standard NaN, Infinity, and -Infinity JSON values in fields of m.room.member events, allowing remote attackers to execute a denial of service attack against the federation and common Matrix clients. If such a malformed event is accepted into th...

py-matrix-synapse -- malformed events may prevent users from joining federated rooms

Problem Description: Affected Synapse versions assume that all events have an "origin" field set. If an event without the "origin" field is sent into a federated room, servers not already joined to the room will be unable to do so due to failing to fetch the malformed event. Impact: An attacker...