CVE-2025-48940Network attack vector

Local file inclusion via unvalidated upgrade action

Published Jun 2, 2025 · Updated Jun 2, 2025

Local file inclusion in MyBB before 1.8.39 allows remote attackers to include local files through the upgrade component's action parameter. The first action segment flows through next_function() and load_module() into require_once without an alphanumeric check, allowing a crafted pathname to select an unintended upgrade module. Exploitation requires an unlocked installer and reachable upgrade script, either before installation, through reinstallation access, or with forum administrator authentication.

CVSS severity7.2
High
EPSS probability0.54%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Local file inclusion in MyBB before 1.8.39 allows remote attackers to include local files through the upgrade component's action parameter. The first action segment flows through next_function() and load_module() into require_once without an alphanumeric check, allowing a crafted pathname to select an unintended upgrade module. Exploitation requires an unlocked installer and reachable upgrade script, either before installation, through reinstallation access, or with forum administrator authentication.

The record

CVE
CVE-2025-48940
Published
Jun 2, 2025
Updated
Jun 2, 2025
Vendor
MyBB
Product
MyBB
Classifications
CWE-22, T1190
Attack vector
network
Privileges
Unavailable

Timeline

How it unfolded

  1. Jun 2, 2025CVE publishedPublication date reported by the CVE source.
  2. Jun 2, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 1.8.39

What conditions does exploitation require?

Attack vectornetwork
Required privilegesUnavailable in this record.

What is affected?

MyBB · MyBBversion=< 1.8.39

Published CVSS scores

7.2GitHubCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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