CVE-2023-53977

5.1 mediumEPSS 0.2%

Medium (5.1) in mybb mybb. EPSS 0.2% chance of exploitation in the next 30 days.

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.

Severity

CVSS 4.0

5.1 medium

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N

CVSS 3.1

5.4 medium

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

EPSS: 0.2% chance of exploitation in the next 30 days; higher than 14% of CVEs (scores of 2026-11-01)
CWE: CWE-79
Published: 2025-12-22
Modified: 2026-06-17
Record from: the NVD, synced 2026-10-19

Affected

mybb:mybb

References

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

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