by Kastro
Paper/Archive/CVE-2026-29204

CVE-2026-29204

WebPros WHMCS — Insufficient ownership check in `clientarea.php` allows an authenticated client area user to submit requests using another user’s `addonI…

EPSS 0.3%CVSS 9.1
critical.is priorityof 100
32
CVSS 9.1 (CNA)9.1 / 10 × 3027.3Not in CISA KEV+300.0EPSS percentile 24.9.249 × 205.0No public exploit+100.0SSVC exploitation: none+100.0
Description · from the CVE record

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.

Affected

ProductAffectedFixed inSource
WHMCS7.4.0 – 18.12.2–CNA
WHMCS18.13.0 – < 18.13.318.13.3CNA
WHMCS9.0.0 – < 9.0.49.0.4CNA

Scores by source

hackerone (CNA)9.1CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
CISA ADPSSVCExploitation: none · Automatable: yes · Technical impact: total

References

refhelp.whmcs.com/m/125386/l/2073908-cve-2026-29204