# WHMCS vulnerabilities

Source: https://junglewise.ai/threats/vendors/whmcs  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Updated: 11 November 2026, 03:07 UTC. Rebuilt every hour.  
Data: https://junglewise.ai/threats/vendors/whmcs.json  
License: CC BY 4.0 with a link back

Junglewise Threat Intelligence has tracked 3 vulnerabilities in WHMCS: 0 in the last 7 days and 2 in the last 90 days, 1 of them critical and 0 exploited in the wild. The most recent, CVE-2026-67399, was published on 14 September 2026. Nothing in the last four weeks, down from 1 vulnerability in the four before. 1 technology has a page of its own.

## Counts

- Last 7 days: 0
- Last 30 days: 0
- Last 90 days: 2
- All time: 3 (1 critical, 0 exploited in the wild)

## About WHMCS

WHMCS is a billing and client management platform designed for web hosting providers and resellers.

## Latest WHMCS vulnerabilities

- [CVE-2026-67399: WHMCS deserialization of untrusted data remote code execution](https://junglewise.ai/threats/cve-2026-67399-whmcs-deserialization-of-untrusted-data-remote-code-execution) (info, CVSS 9.8, published 14 Sep 2026)
- [CVE-2026-67398: WHMCS 2Checkout payment gateway authorization bypass](https://junglewise.ai/threats/cve-2026-67398-whmcs-2checkout-payment-gateway-authorization-bypass) (info, published 4 Sep 2026)
- [CVE-2026-29204: WHMCS authorization bypass in clientarea.php via addonId](https://junglewise.ai/threats/cve-2026-29204-whmcs-authorization-bypass-in-clientarea-php-via-addonid) (critical, CVSS 9.1, published 12 May 2026)

## Most severe WHMCS vulnerabilities

- [CVE-2026-29204: WHMCS authorization bypass in clientarea.php via addonId](https://junglewise.ai/threats/cve-2026-29204-whmcs-authorization-bypass-in-clientarea-php-via-addonid) (critical, CVSS 9.1, published 12 May 2026)
- [CVE-2026-67399: WHMCS deserialization of untrusted data remote code execution](https://junglewise.ai/threats/cve-2026-67399-whmcs-deserialization-of-untrusted-data-remote-code-execution) (info, CVSS 9.8, published 14 Sep 2026)
- [CVE-2026-67398: WHMCS 2Checkout payment gateway authorization bypass](https://junglewise.ai/threats/cve-2026-67398-whmcs-2checkout-payment-gateway-authorization-bypass) (info, published 4 Sep 2026)

## Vulnerabilities per week

Nothing in the last four weeks, down from 1 vulnerability in the four before.

| Week of | Vulns | Critical | Exploited |
| --- | --- | --- | --- |
| 17 Aug 2026 | 0 | 0 | 0 |
| 24 Aug 2026 | 0 | 0 | 0 |
| 31 Aug 2026 | 1 | 0 | 0 |
| 7 Sep 2026 | 0 | 0 | 0 |
| 14 Sep 2026 | 1 | 0 | 0 |
| 21 Sep 2026 | 0 | 0 | 0 |
| 28 Sep 2026 | 0 | 0 | 0 |
| 5 Oct 2026 | 0 | 0 | 0 |
| 12 Oct 2026 | 0 | 0 | 0 |
| 19 Oct 2026 | 0 | 0 | 0 |
| 26 Oct 2026 | 0 | 0 | 0 |
| 2 Nov 2026 | 0 | 0 | 0 |
| 9 Nov 2026 | 0 | 0 | 0 |

## WHMCS technologies

- [WHMCS](https://junglewise.ai/threats/technologies/whmcs): 3 vulnerabilities

## Sources

NVD, GitHub Security Advisories, OSV, the CISA Known Exploited Vulnerabilities catalog, FIRST EPSS and vendor advisories. Rebuilt every hour. Cite as: Junglewise Threat Intelligence, "WHMCS vulnerabilities", https://junglewise.ai/threats/vendors/whmcs, 11 November 2026.