CVE-2025-66622: matrix-rust-sdk — Fix

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.

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CVSS v3.1 Score

7.5

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Weakness Type (CWE)

CWE-755 CWE-755

Affected Products

Vendor	Product	Versions
matrix	matrix-rust-sdk	< 0.16.0

References

Advisories & Patches

https://github.com/matrix-org/matrix-rust-sdk/commit/4ea0418abefab2aa93f8851a4d39c723e703e6b0 https://github.com/matrix-org/matrix-rust-sdk/pull/5924 https://github.com/matrix-org/matrix-rust-sdk/security/advisories/GHSA-jj6p-3m75-g2p3

Other References

https://rustsec.org/advisories/RUSTSEC-2025-0135.html

Frequently Asked Questions

What is CVE-2025-66622? +

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. It has a CVSS v3.1 base score of 7.5 (HIGH).

How severe is CVE-2025-66622? +

CVE-2025-66622 has a CVSS v3.1 score of 7.5 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.

What products are affected by CVE-2025-66622? +

CVE-2025-66622 affects products from matrix, specifically: matrix-rust-sdk. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2025-66622? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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