CVE-2025-48940

MyBB's upgrade component vulnerable to local file inclusion

Published Jun 2, 2025 CVSS 3.1 · 7.2 High EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
EUVD EUVD EUVD-2025-16668 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.
History
Type Values Removed Values Added
First Time appeared Mybb
Mybb mybb
CPEs cpe:2.3:a:mybb:mybb:*:*:*:*:*:*:*:*
Vendors & Products Mybb
Mybb mybb
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
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.
Title MyBB's upgrade component vulnerable to local file inclusion
Weaknesses CWE-22
References
Metrics cvssV3_1

{'score': 7.2, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Jun 2, 2025, 4:06 PM
Reserved
May 28, 2025, 6:49 PM
Status
Analyzed
Published
Jun 2, 2025, 4:15 PM
Modified
Jun 17, 2026, 9:30 AM