Critical severity · published May 12, 2026
CVE-2026-29204
Insufficient ownership check in `clientarea.php` allows an authenticated client area user to submit requests using another user’s `addonId` without any ownership validation…
9.1
CVSS
0.3%
EPSS
No
On KEV
Description
Insufficient ownership check in `clientarea.php` allows an authenticated client area user to submit requests using another user’s `addonId` without any ownership validation leading to unauthorized access to the victim's account.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 25% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
WH
WHMCS · WebPros
7.4.0 through 18.12.2; 18.13.0 before 18.13.3; 9.0.0 before 9.0.4 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-29204
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-29204
help.whmcs.com
https://help.whmcs.com/m/125386/l/2073908-cve-2026-29204
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