Vulnerabilities

Vulnerability · CVE-2011-10018

myBB version 1.6.4 was distributed with an unauthorized backdoor embedded in the source code.

Published Aug 13, 2025 · catalog updated Apr 7, 2026 · myBB Group Forum Software

Check if you run it

No confirmed exploitation is on record for CVE-2011-10018. EPSS is 2.85%. Act only if a listed version of myBB Group Forum Software is installed.

Gaps on this record

  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
Critical10.0
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
2.85%
Remediation
Advisory link
Affected products
vendor myBB Group Forum Software 1.6.4

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.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • vendor myBB Group Forum Software 1.6.41.6.4

How to fix CVE-2011-10018

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2011-10018. EPSS is 2.85%. Act only if a listed version of myBB Group Forum Software is installed.

Which versions are affected?

Compare what you have installed with myBB Group Forum Software 1.6.4 1.6.4. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

No weakness class is stored. EPSS 2.85%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Aug 13, 2025 · EUVD

    Detected

    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

  2. Apr 7, 2026 · EUVD

    Updated

    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

Sources

  • CVE.orgVulnerability recordCVE-2011-10018

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2011-10018

    30-day exploitation probability 2.85%

    first.org
  • EUVDVulnerability recordEUVD-2011-5246

    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 an

    euvd.enisa.europa.eu

References

Freshness

Last verified in this catalog Oct 21, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.