What is CVE-2021-3780?

CVE-2021-3780 is a medium-severity vulnerability in Chocobozzz Chocobozzz/peertube, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2021-09-15.

How severe is CVE-2021-3780?

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

XSS in Chocobozzz Chocobozzz/peertube

CVE-2021-3780

peertube is vulnerable to Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Vulnerability class: XSS (Cross-Site Scripting)

Published 2021-09-15 · 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 (58.0th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 58th percentile — 58.0% 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

Chocobozzz Chocobozzz/peertube — versions unspecified
Framasoft Peertube

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

huntr.dev/bounties/282807a8-4bf5-4fe2-af62-e05f945b3d65 (Exploit, Third Party Advisory)
github.com/chocobozzz/peertube/commit/0ea2f79d45b301fcd660efc894469a99b2239bf6 (Patch, Third Party Advisory)

Frequently asked questions

What is CVE-2021-3780?: CVE-2021-3780 is a medium-severity vulnerability in Chocobozzz Chocobozzz/peertube, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2021-09-15.
How severe is CVE-2021-3780?: Medium severity. CVSS v3 base score is 6.1 out of 10.