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CVE-2026-67399 | Mondoo Vulnerability Intelligence

Vulnerability IntelligenceCVE-2026-67399

CVE-2026-67399

CRITICAL9.3

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

Published Sep 14, 2026

Modified Yesterday

Details

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.

References

https://help.whmcs.com/m/125386/l/2118034-cve-2026-67399-whmcs-security-update-2026-09-03

https://www.cve.org/CVERecord?id=CVE-2026-67399

CVSS Analysis

CVSS v4.0

9.3

Exploitability

Attack Vector

NetworkAV:N

Attack Complexity

LowAC:L

Attack Requirements

NoneAT:N

Privileges Required

NonePR:N

User Interaction

NoneUI:N

Vulnerable System

Vuln. Confidentiality

HighVC:H

Vuln. Integrity

HighVI:H

Vuln. Availability

HighVA:H

Subsequent System

Subseq. Confidentiality

NoneSC:N

Subseq. Integrity

NoneSI:N

Subseq. Availability

NoneSA:N

9.3/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

Weakness Type (CWE)

Serialization

Deserialization of Untrusted Data

Ecosystems

Timeline

PublishedSep 14, 2026

ModifiedSep 15, 2026