CVE-2026-56843
Critical
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.
SeverityCritical
CVSS9.9
Exploit probability—
Product
Plesk
PublishedJul 8, 2026
First seenJul 8, 2026
Weakness typeCWE-522CWE-522
How to fix
Update
- Webpros Plesk18.0.78.4 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| Webpros Plesk | 10.4 ≤ v < 18.0.78.4 | 18.0.78.4 |
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