CVE-2023-53977

MEDIUM 5.4

myBB Forums 1.8.26 Stored Cross-Site Scripting via Forum Management

CVSS Score

5.4

EPSS Score

0.0%

EPSS Percentile

0th

myBB Forums 1.8.26 contains a stored cross-site scripting vulnerability in the forum management system that allows authenticated administrators to inject malicious scripts when creating new forums. Attackers can exploit this vulnerability by inserting script payloads in the forum title field when adding new forums through the 'Forums and Posts' > 'Forum Management' interface, causing arbitrary JavaScript to execute when the forum listing is viewed.

CWE	CWE-79
Vendor	mybb
Product	mybb forums
Published	Dec 22, 2025
Last Updated	Apr 7, 2026

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CVSS v3 Breakdown

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

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

Required

Scope

Changed

Confidentiality

Low

Integrity

Low

Availability

None

Affected Versions

Mybb / myBB forums

1.8.26

References

NVD ↗ CVE.org ↗ EPSS Data ↗

exploit-db.com: https://www.exploit-db.com/exploits/51136 mybb.com: https://mybb.com/ vulncheck.com: https://www.vulncheck.com/advisories/mybb-forums-stored-cross-site-scripting-via-forum-management

Credits

Andrey Stoykov