XSS in Mybb
CVE-2023-53976
myBB Forums 1.8.26 contains a stored cross-site scripting vulnerability in the template management system that allows authenticated administrators to inject malicious scripts when creating new templates. Attackers can exploit this vulnerability by inserting script payloads in the template title field when adding new templates through the 'Templates and Style' > 'Templates' > 'Manage Templates' > 'Global Templates' interface, causing arbitrary JavaScript to execute when the template is viewed.
Vulnerability class: XSS (Cross-Site Scripting)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N.
EPSS exploit prediction
EPSS: 0.002 (14.0th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 14th percentile — 14.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: +0.000
Affected products
- Mybb — versions 1.8.26
- Mybb Forums — versions 1.8.26
Weakness classification (CWE)
References
- www.exploit-db.com/exploits/51136 (Exploit, exploit)
- mybb.com/ (Product, product)
- www.vulncheck.com/advisories/mybb-forums-stored-cross-site-scripting-via-templa… (Exploit, Third Party Advisory, third-party-advisory)
- af854a3a-2127-422b-91ae-364da2661108
Frequently asked questions
- What is CVE-2023-53976?
- CVE-2023-53976 is a medium-severity vulnerability in Mybb, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2025-12-22.
- How severe is CVE-2023-53976?
- Medium severity. CVSS v3 base score is 5.4 out of 10.