Privilege escalation in Webpros Plesk

CVE-2026-64637

Improper privilege management in the XML-RPC API of Plesk before 18.0.80, allows an authenticated reseller to obtain an administrative session for the root user account.

Vulnerability class: Privilege Escalation

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.9 (Critical). Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.005 (40.8th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 41st percentile — 40.8% 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-2026-64637: held from 0.005 to 0.005.

EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-64637?
CVE-2026-64637 is a critical-severity vulnerability in Webpros Plesk, classified under Improper Privilege Management. CVSS score: 9.9/10. Published 2026-08-07.
How severe is CVE-2026-64637?
Critical severity. CVSS v3 base score is 9.9 out of 10.