XSS in Couchcms
CVE-2021-47955
CouchCMS 2.2.1 contains a cross-site scripting vulnerability that allows authenticated attackers to execute arbitrary JavaScript by uploading malicious SVG files through the file upload functionality. Attackers can upload SVG files containing embedded script tags to the browse.php endpoint, which are then executed in users' browsers when the files are accessed or previewed.
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 (5.9th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 6th percentile — 5.9% 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
- Couchcms — versions 2.2.1
Weakness classification (CWE)
References
- www.exploit-db.com/exploits/49636 (exploit)
- github.com/CouchCMS/CouchCMS (product)
- www.vulncheck.com/advisories/couchcms-cross-site-scripting-via-svg-file-upload (third-party-advisory)
Frequently asked questions
- What is CVE-2021-47955?
- CVE-2021-47955 is a medium-severity vulnerability in Couchcms, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2026-05-16.
- How severe is CVE-2021-47955?
- Medium severity. CVSS v3 base score is 5.4 out of 10.