What is CVE-2020-8120?

CVE-2020-8120 is a medium-severity vulnerability in Nextcloud Server, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2020-02-04.

How severe is CVE-2020-8120?

Medium severity. CVSS v3 base score is 6.1 out of 10.

XSS in Nextcloud Server

CVE-2020-8120

A reflected Cross-Site Scripting vulnerability in Nextcloud Server 16.0.1 was discovered in the svg generation.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2020-02-04 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.009 (58.6th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 59th percentile — 58.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.009 · newest: 0.009 · change: 0.000

Affected products

Nextcloud Server — versions 16.0.1
Nextcloud Server — versions 16.0.1

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

hackerone.com/reports/605915 (Exploit, Third Party Advisory)
nextcloud.com/security/advisory/ (Broken Link, Vendor Advisory)

Frequently asked questions

What is CVE-2020-8120?: CVE-2020-8120 is a medium-severity vulnerability in Nextcloud Server, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2020-02-04.
How severe is CVE-2020-8120?: Medium severity. CVSS v3 base score is 6.1 out of 10.