What is CVE-2019-18835?

CVE-2019-18835 is a critical-severity vulnerability in Matrix Synapse, classified under Insufficient Verification of Data Authenticity. CVSS score: 9.8/10. Published 2019-11-08.

How severe is CVE-2019-18835?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Vulnerability in Matrix Synapse

CVE-2019-18835

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.

EPSS: 0.009 (54.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Matrix Synapse
N/a — versions n/a

Weakness classification (CWE)

CWE-345 — Insufficient Verification of Data Authenticity

References

cve@mitre.org (Patch, Third Party Advisory, x_refsource_MISC)
cve@mitre.org (Third Party Advisory, x_refsource_MISC, Release Notes)

Frequently asked questions

What is CVE-2019-18835?: CVE-2019-18835 is a critical-severity vulnerability in Matrix Synapse, classified under Insufficient Verification of Data Authenticity. CVSS score: 9.8/10. Published 2019-11-08.
How severe is CVE-2019-18835?: Critical severity. CVSS v3 base score is 9.8 out of 10.