CVE-2026-45127
LOW
3,5
Source: [email protected]
Attack Vector: network
Attack Complexity: low
Privileges Required: low
User Interaction: required
Scope: unchanged
Confidentiality: none
Integrity: low
Availability: none
Description
AI Translation Available
MyBB is free and open source forum software. Prior to 1.8.40, the ACP Mass Mail module does not validate certain requests correctly, allowing same-site attackers to create draft entries from archived entries by embedding a specially crafted URL. The Resend route in Admin CP, Users & Groups, Mass Mail, Mass Mailing Archive duplicates archived mailing entries into new drafts with mybb_massemails.status set to 0 on GET requests without request forgery protection. The uniquely identifying implementation details include Users & Groups → Mass Mail → Mass Mailing Archive, mybb_massemails.status = 0, and admin/modules/user/mass_mail.php. This issue is fixed in version 1.8.40.
352
Cross-Site Request Forgery (CSRF)
StableCommon Consequences
Security Scopes Affected:
Confidentiality
Integrity
Availability
Non-Repudiation
Access Control
Potential Impacts:
Gain Privileges Or Assume Identity
Bypass Protection Mechanism
Read Application Data
Modify Application Data
Dos: Crash, Exit, Or Restart
Applicable Platforms
Technologies:
Web Based, Web Server
https://github.com/mybb/mybb/commit/a95c5d6730b943adab7e54bc209c051f98843a3b
https://github.com/mybb/mybb/releases/tag/mybb_1840
https://github.com/mybb/mybb/security/advisories/GHSA-xx78-g79m-qvgq
https://mybb.com/versions/1.8.40