CVE-2026-67399 Details
Description
Deserialization of untrusted data in WHMCS 9.0.0 before 9.0.8 and 8.0.0 before 8.13.7 allows remote attackers to execute arbitrary code.
A deserialization vulnerability has been identified in WHMCS versions 9.0.0 prior to 9.0.8 and 8.0.0 prior to 8.13.7. This vulnerability allows remote attackers to execute arbitrary code by sending crafted payloads that are not properly validated. The issue arises from the application’s handling of serialized data, which can be exploited under certain conditions to achieve remote code execution on the server.
Users are advised to update to WHMCS version 9.0.8 or 8.13.7, depending on their current version.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Sep 14, 2026CISA-ADP
Assessed Sep 15, 2026References to Advisories, Solutions, and Tools
By selecting these links, you will be leaving this site. These are references gathered from the official CVE record and are not endorsed by Volerion.
| URL | Source(s) | Tag(s) |
|---|---|---|
| https://help.whmcs.com/m/125386/l/2118034-cve-2026-67399-whmcs-security-update-2026-09-03 | [email protected] | AdvisoryRemedyVendor |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-502 | Deserialization of Untrusted Data | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| WHMCS | >= 9.0.0, < 9.0.8 (semver) >= 8.0.0, < 8.13.7 (semver) |
CPE
Remediation
| |
Change History
2 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Sep 15, 2026 | CVE Modified | CISA-ADP |
| Sep 14, 2026 | New CVE Received | [email protected] |