VULNERABILITY INTELLIGENCE

CVE-2025-48940

CVSS score7.2 HIGH
EPSS probability0.56%
CISA KEVNot currently listed
Published2025-06-02
Last modified2026-06-17
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

Description

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.

Weakness classification

  • CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

Primary references