CVE-2026-45120 — MEDIUM (5.4)

Vulnerability Description

MyBB is free and open source forum software. Prior to 1.8.40, the calendar module does not verify private event status consistently, allowing users with viewing and moderation permissions to access and moderate private events. The private-event check used by get_events() in inc/functions_calendar.php and the event action is missing from the remaining calendar.php actions, despite the limited-access behavior described in inc/languages/english/calendar.lang.php. This issue is fixed in version 1.8.40.

CVSS Score

5.4

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality

LOW

Integrity

LOW

Availability

NONE

Related Weaknesses (CWE)

CWE-639

References

FAQ

What is CVE-2026-45120?

CVE-2026-45120 is a vulnerability with a CVSS score of 5.4 (MEDIUM). MyBB is free and open source forum software. Prior to 1.8.40, the calendar module does not verify private event status consistently, allowing users with viewing and moderation permissions to access an...

How severe is CVE-2026-45120?

CVE-2026-45120 has been rated MEDIUM with a CVSS base score of 5.4/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-45120?

Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.