CVE-2025-48940

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.

CVSS v3 7.2 HIGH

7.2^/10

CVSS v3 : HIGH

Vector :

Exploitability : 1.2 / Impact : 5.9

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required HIGH

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://github.com/mybb/mybb/commit/6e6cfbd524d9101b51e1278ecf520479b64b0f00	Patch
https://github.com/mybb/mybb/security/advisories/GHSA-q4jv-xwjx-37cp	Vendor Advisory
https://mybb.com/versions/1.8.39	Product Release Notes

Configurations

Configuration 1 (hide)

cpe:2.3:a:mybb:mybb:*:*:*:*:*:*:*:*

History

02 Jul 2025, 15:18

Type	Values Removed	Values Added
New CVE

Information

Published : 2025-06-02 16:15

Updated : 2025-07-02 15:18

NVD link : CVE-2025-48940

Mitre link : CVE-2025-48940

CVE.ORG link : CVE-2025-48940

JSON object : View

Products Affected

mybb

mybb

CWE

CWE-22

Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

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