CVE-2019-18835: Matrix Synapse before 1.5.0 mishandles signature checking on some fede ...

Severity: Critical

CVSS Score: 8.6

Matrix Synapse before 1.5.0 mishandles signature checking on some federation APIs. Events sent over /send_join, /send_leave, and /invite may not be correctly signed, or may not come from the expected servers.