Matrix Synapse before 1.5.0 mishandles signature checking on some federation APIs. Events sent over /sendjoin, /sendleave, and /invite may not be correctly signed, or may not come from the expected servers.
{ "urgency": "not yet assigned" }
"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2019-18835.json"