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.

Metrics

Attack Vector Network

Attack Complexity Low

Privileges Required None

Attack Requirements None

User Interaction None

Vulnerable System Confidentiality Impact High

Vulnerable System Integrity Impact High

Vulnerable System Availability Impact High

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

No CVSS v3.1

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

Affected Vendors & Products

No data.

No data.

No data.

No data.

Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://help.whmcs.com/m/125386/l/2118034-cve-2026-67399-whmcs-security-update-2026-09-03 cve-icon cve-icon
History

Mon, 14 Sep 2026 21:00:00 +0000

Type Values Removed Values Added
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.
Weaknesses CWE-502
References
Metrics cvssV4_0

{'score': 9.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N'}

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: hackerone

Published:

Updated: 2026-09-14T20:53:05.620Z

Reserved: 2026-07-29T15:00:02.294Z

Link: CVE-2026-67399

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-09-14T21:17:25.423

Modified: 2026-09-14T21:17:25.423

Link: CVE-2026-67399

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses