Vulnerability in Matrix Matrix-rust-sdk

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 deni…

EPSS: 0.004 (29.3th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-66622?
CVE-2025-66622 is a high-severity vulnerability in Matrix Matrix-rust-sdk, classified under Improper Handling of Exceptional Conditions. CVSS score: 7.5/10. Published 2025-12-09.
How severe is CVE-2025-66622?
High severity. CVSS v3 base score is 7.5 out of 10.