CVE-2011-10018 myBB 1.6.4 Backdoor Arbitrary Command Execution

What is CVE-2011-10018?

CVE-2011-10018 is a critical vulnerability in Mybb Mybb, published on 13 Aug 2025.

Official description

myBB version 1.6.4 was distributed with an unauthorized backdoor embedded in the source code. The backdoor allowed remote attackers to execute arbitrary PHP code by injecting payloads into a specially crafted collapsed cookie. This vulnerability was introduced during packaging and was not part of the intended application logic. Exploitation requires no authentication and results in full compromise of the web server under the context of the web application.

Weakness: CWE-94, CWE-912

Which versions are affected by CVE-2011-10018?

It affects 1 product.

Products include Mybb Mybb.

How do I fix CVE-2011-10018?

No fix has been published for CVE-2011-10018 yet. Limit exposure of the affected software until one is available.

Is CVE-2011-10018 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2011-10018 exists.

Public exploit code: 1 Metasploit module.

Other vulnerabilities in Mybb Mybb

• CVE-2015-2786 Information disclosure in n/a Critical 10.0
• CVE-2011-5133 Cross-site scripting in n/a Critical 10.0
• CVE-2006-0218 SQL injection in n/a Critical 10.0
• CVE-2020-22612 Code injection in n/a Critical 9.8
• CVE-2017-16780 Code injection in n/a Critical 9.8

All Mybb Mybb vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-4whv-mhhp-7qcj.