Critical severity · published Jul 8, 2026
CVE-2026-56843
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…
9.9
CVSS
0.7%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.7% · higher than 51% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
PL
Plesk · Webpros
10.4 before 18.0.78.4 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-56843
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-56843
support.plesk.com
https://support.plesk.com/hc/en-us/articles/41178305151255-Vulnerability-in-Plesk-XML-API-Cleartext-FTP-Password-Exposure
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