Is CVE-2026-56843 being exploited?

No public exploit is currently tracked.

How severe is CVE-2026-56843?

CVE-2026-56843 has a CVSS v3 severity of CRITICAL (9.9).

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CVE-2026-56843

Description

Incorrect authorization in the XML-RPC API of WebPros Plesk before 18.0.78.4 allows a low-privileged authenticated customer to look up domains they do not own, because ownership is enforced only for certain lookup filters and schema validation is bypassed for legacy protocol versions. This results in cross-tenant disclosure of other tenants' FTP credentials stored in cleartext, which can be leveraged to execute code as another tenant's system user.