What is CVE-2026-3564?

CVE-2026-3564 is a critical-severity vulnerability in Connectwise Screenconnect, classified under Improper Verification of Cryptographic Signature. CVSS score: 9.0/10. Published 2026-03-17.

How severe is CVE-2026-3564?

Critical severity. CVSS v3 base score is 9.0 out of 10.

Vulnerability in Connectwise Screenconnect

CVE-2026-3564

A condition in ScreenConnect may allow an actor with access to server-level cryptographic material used for authentication to obtain unauthorized access, including elevated privileges, in certain scenarios.

EPSS: 0.000 (8.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.0 (Critical). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H.

Affected products

Connectwise Screenconnect — versions All versions prior to 26.1

Weakness classification (CWE)

CWE-347 — Improper Verification of Cryptographic Signature

References

www.connectwise.com/company/trust/security-bulletins/2026-03-17-screenconnect-b…

Frequently asked questions

What is CVE-2026-3564?: CVE-2026-3564 is a critical-severity vulnerability in Connectwise Screenconnect, classified under Improper Verification of Cryptographic Signature. CVSS score: 9.0/10. Published 2026-03-17.
How severe is CVE-2026-3564?: Critical severity. CVSS v3 base score is 9.0 out of 10.