VULNERABILITY INTELLIGENCE

CVE-2019-18835

CVSS score9.8 CRITICAL

EPSS probability0.86%

CISA KEVNot currently listed

Published2019-11-08

Last modified2026-06-17

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

Description

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.

Weakness classification

CWE-345: Insufficient Verification of Data Authenticity

Primary references

cve@mitre.org — Patch, Third Party Advisory
cve@mitre.org — Release Notes, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108 — Patch, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108 — Release Notes, Third Party Advisory