XSS in Exponentcms Exponent Cms
CVE-2021-47931
Exponent CMS 2.6 contains a stored cross-site scripting vulnerability that allows authenticated attackers to inject malicious scripts through the Title and Text Block parameters in the text editing endpoint. Attackers can inject iframe payloads with embedded SVG onload events to execute arbitrary JavaScript. The application also exposes database credentials in responses and lacks brute-force protection on authentication endpoints.
Vulnerability class: XSS (Cross-Site Scripting)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N.
EPSS exploit prediction
EPSS: 0.002 (10.4th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 10th percentile — 10.4% 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
- Exponentcms Exponent Cms — versions 0
Weakness classification (CWE)
References
- www.exploit-db.com/exploits/50611 (exploit)
- www.exponentcms.org/ (product)
- www.vulncheck.com/advisories/exponent-cms-multiple-vulnerabilities-stored-xss-a… (third-party-advisory)
Frequently asked questions
- What is CVE-2021-47931?
- CVE-2021-47931 is a medium-severity vulnerability in Exponentcms Exponent Cms, classified under Cross-site Scripting. CVSS score: 6.4/10. Published 2026-05-10.
- How severe is CVE-2021-47931?
- Medium severity. CVSS v3 base score is 6.4 out of 10.