CVE-2025-48940
June 02, 2025
MyBB is free and open source forum software. Prior to version 1.8.39, the upgrade component does not validate user input properly, which allows attackers to perform local file inclusion (LFI) via a specially crafted parameter value. In order to exploit the vulnerability, the installer must be unlocked (no "install/lock" file present) and the upgrade script must be accessible (by re-installing the forum via access to "install/index.php"; when the forum has not yet been installed; or the attacker is authenticated as a forum administrator). MyBB 1.8.39 resolves this issue.
Affected Packages
https://github.com/mybb/mybb.git (GITHUB):
Affected version(s) >=mybb_1.00 <mybb_1839Fix Suggestion:
Update to version mybb_1839Additional Notes
The description of this vulnerability differs from MITRE.
Related Resources (3)
Do you need more information?
Contact UsCVSS v4
Base Score:
8.6
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
HIGH
User Interaction
NONE
Vulnerable System Confidentiality
HIGH
Vulnerable System Integrity
HIGH
Vulnerable System Availability
HIGH
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
7.2
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
HIGH
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Weakness Type (CWE)
Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
EPSS
Base Score:
0.14
