Vulnerability in Connectwise Screenconnect

CVE-2026-3564

A condition in the ScreenConnect server component may allow an actor with access to server-level cryptographic material used for authentication to obtain unauthorized access, including elevated privileges, in certain scenarios. ScreenConnect host and guest client agents are not independently affected by this CVE.

Published · last modified .

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.

EPSS exploit prediction

EPSS: 0.003 (18.8th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 19th percentile — 18.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-3564: held from 0.004 to 0.003.

EPSS over last 30 days · oldest: 0.004 · newest: 0.003 · change: -0.001

Affected products

Weakness classification (CWE)

References

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.