XSS in Kentico Xperience
CVE-2020-36891
A stored cross-site scripting vulnerability in Kentico Xperience allows attackers to upload files with spoofed Content-Type that do not match file extensions. Attackers can exploit this vulnerability by uploading malicious files with manipulated MIME types, allowing malicious scripts to execute in users' browsers.
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 (10.9th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 11th percentile — 10.9% 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
- Kentico Xperience — versions 0
Weakness classification (CWE)
References
- devnet.kentico.com/download/hotfixes (Product, vendor-advisory, patch)
- www.vulncheck.com/advisories/kentico-xperience-file-upload-stored-xss (Third Party Advisory, third-party-advisory)
Frequently asked questions
- What is CVE-2020-36891?
- CVE-2020-36891 is a medium-severity vulnerability in Kentico Xperience, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2025-12-18.
- How severe is CVE-2020-36891?
- Medium severity. CVSS v3 base score is 5.4 out of 10.