CVE-2025-66622
matrix-sdk-base is vulnerable to DoS via custom m.room.join_rules event values
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.
INFO
Published Date :
Dec. 9, 2025, 4:18 p.m.
Last Modified :
March 17, 2026, 8:27 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | [email protected] | ||||
| CVSS 4.0 | LOW | [email protected] |
Solution
- Update matrix-sdk-base to version 0.16.0 or later.
- Apply the latest security patches for the library.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2025-66622.
| URL | Resource |
|---|---|
| https://github.com/matrix-org/matrix-rust-sdk/commit/4ea0418abefab2aa93f8851a4d39c723e703e6b0 | Patch |
| https://github.com/matrix-org/matrix-rust-sdk/pull/5924 | Issue Tracking Patch |
| https://github.com/matrix-org/matrix-rust-sdk/security/advisories/GHSA-jj6p-3m75-g2p3 | Patch Vendor Advisory |
| https://rustsec.org/advisories/RUSTSEC-2025-0135.html | Third Party Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2025-66622 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2025-66622
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2025-66622 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2025-66622 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Mar. 17, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Added CPE Configuration OR *cpe:2.3:a:matrix:matrix-rust-sdk:*:*:*:*:*:*:*:* versions up to (excluding) 0.16.0 Added Reference Type GitHub, Inc.: https://github.com/matrix-org/matrix-rust-sdk/commit/4ea0418abefab2aa93f8851a4d39c723e703e6b0 Types: Patch Added Reference Type GitHub, Inc.: https://github.com/matrix-org/matrix-rust-sdk/pull/5924 Types: Issue Tracking, Patch Added Reference Type GitHub, Inc.: https://github.com/matrix-org/matrix-rust-sdk/security/advisories/GHSA-jj6p-3m75-g2p3 Types: Patch, Vendor Advisory Added Reference Type GitHub, Inc.: https://rustsec.org/advisories/RUSTSEC-2025-0135.html Types: Third Party Advisory -
New CVE Received by [email protected]
Dec. 09, 2025
Action Type Old Value New Value Added 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. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CWE CWE-755 Added Reference https://github.com/matrix-org/matrix-rust-sdk/commit/4ea0418abefab2aa93f8851a4d39c723e703e6b0 Added Reference https://github.com/matrix-org/matrix-rust-sdk/pull/5924 Added Reference https://github.com/matrix-org/matrix-rust-sdk/security/advisories/GHSA-jj6p-3m75-g2p3 Added Reference https://rustsec.org/advisories/RUSTSEC-2025-0135.html