CVE-2026-45122
MyBB: Insufficient permission check for calendar event move
- State
- Published
- Severity
- 4.3 Medium
- Published
- Aug 18, 2026
- Updated
- Aug 18, 2026
- Reserved
- May 8, 2026
Description
MyBB is free and open source forum software. Prior to 1.8.40, the calendar module does not validate moderation permissions for the destination calendar when moving events. A user with moderation permission for the source calendar can move an event to a calendar where the user has only viewing permission because the do_move action in calendar.php does not check canmoderateevents for the target calendar. The uniquely identifying implementation details include calendar event move, source calendar moderation permission, and destination calendar viewing permission. This issue is fixed in version 1.8.40.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 4.3 Medium | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N | GitHub_M |
Weaknesses
- CWE-863 Incorrect Authorization
Affected Products
| Product | Versions |
|---|---|
mybbmybb |
|
References
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