BaseFortify

Publication date: 2025-12-09

Last updated on: 2026-03-17

Assigner: GitHub, Inc.

Description

matrix-sdk-base is the base component to build a Matrix client library. Versions 0.14.1 and prior are unable to handle responses that include custom m.room.join_rules values due to a serialization bug. This can be exploited to cause a denial-of-service condition, if a user is invited to a room with non-standard join rules, the crate's sync process will stall, preventing further processing for all rooms. This is fixed in version 0.16.0.

CVSS Scores

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Meta Information

Published

2025-12-09

Last Modified

2026-03-17

Generated

2026-07-06

AI Q&A

2025-12-09

EPSS Evaluated

2026-07-05

NVD

CVE-2025-66622

Affected Vendors & Products

Vendor	Product	Version / Range
matrix	matrix-rust-sdk	to 0.16.0 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-755	The product does not handle or incorrectly handles an exceptional condition.

Attack-Flow Graph

Executive Summary

The vulnerability exists in matrix-sdk-base versions 0.14.1 and prior, where the software cannot properly handle responses containing custom m.room.join_rules values due to a serialization bug. If a user is invited to a room with non-standard join rules, the synchronization process stalls, causing a denial-of-service condition that prevents further processing for all rooms.

Impact Analysis

This vulnerability can cause a denial-of-service condition in the matrix-sdk-base client library. Specifically, if a user is invited to a room with non-standard join rules, the synchronization process will stall and stop processing updates for all rooms, potentially disrupting normal application functionality.

Mitigation Strategies

Upgrade matrix-sdk-base to version 0.16.0 or later, as this version fixes the serialization bug causing the denial-of-service condition.

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