Vulnerability · Published Sep 14, 2026 · Assigned by hackerone
CVE-2026-67399
Critical 9.3
In plain English
A critical-severity unsafe deserialization in WHMCS from WebPros. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.8% (higher than 55% of all known vulnerabilities).
Severity (CVSS 4.0)9.3Critical
Exploit odds (30 days)0.8%top 44.8% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official 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.
Affected products (as reported)
Weakness: CWE-502 · 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