CVE-2026-67399 PUBLISHED

Assigner: hackerone
Reserved: 29.07.2026 Published: 14.09.2026 Updated: 15.09.2026

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.

CVSS 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
CVSS Score: 9.3

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	High	Confidentiality	None
Attack Complexity	Low	Integrity	High	Integrity	None
Attack Requirements	None	Availability	High	Availability	None
Privileges Required	None
User Interaction	None

CVSS 4.0

Vendor	WebPros
Product	WHMCS
Versions	Default: unaffected affected from 9.0.0 to 9.0.8 (excl.) affected from 8.0.0 to 8.13.7 (excl.)