WebPros Plesk before version 18.0.80.1 is affected by CVE-2026-64637, an improper privilege management flaw in the XML-RPC API that allows an authenticated reseller to obtain an administrative session for the root user account. The vulnerability is classified as CWE-269 and carries a high-severity CVSS v3 vector of AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H, indicating low attack complexity and potentially severe impact on confidentiality, integrity, and availability.
A related advisory from CERT-PY flagged the issue in Plesk products, reinforcing the risk to organizations that use the hosting control panel in multi-tenant or reseller environments. Available records indicate the flaw is not currently assessed as exploited in the wild and is not considered automatable, but its ability to let a lower-privileged authenticated user escalate directly to root-level administration makes prompt upgrading to 18.0.80.1 or later a priority.

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3 events from the most recent confirmed update back to the earliest known activity.
A CISA SSVC entry was added for CVE-2026-64637, assessing exploitation as none, automatable as no, and technical impact as total. The entry identifies the role as CISA Coordinator and version 2.0.3.
CVE-2026-64637 was newly received for an improper privilege management flaw in the WebPros Plesk XML-RPC API affecting versions before 18.0.80.1. The vulnerability allows an authenticated reseller to obtain an administrative session for the root user account.
CERT-PY published an advisory titled "Vulnerabilidad en productos Plesk." The provided reference confirms the advisory exists, but the available content does not expose further event details.
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