Is CVE-2021-39183 actively exploited?

No active exploitation of CVE-2021-39183 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2021-39183 be exploited remotely?

Yes. CVE-2021-39183 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2021-39183?

CVE-2021-39183 has a CVSS score of 6.1 (MEDIUM).

HOME VULNERABILITIESCVE-2021-39183

MEDIUM

CVE-2021-39183

CWE-79Published: December 14, 2021· Updated: Jun 17, 2026

6.1

CVSS v3.1

Official Description

Owncast is an open source, self-hosted live video streaming and chat server. In affected versions inline scripts are executed when Javascript is parsed via a paste action. This issue is patched in 0.0.9 by blocking unsafe-inline Content Security Policy and specifying the script-src. The worker-src is required to be set to blob for the video player.

NVD Source

Technical Analysis

CVE-2021-39183 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

Exploitation does not require any privileges, though user interaction (Required) is needed, which slightly reduces the risk of mass automated attacks.

The vulnerability has a "Changed" scope, meaning successful exploitation can impact components beyond the vulnerable component itself — such as the host operating system or adjacent services.

From a weakness classification perspective (CWE-79): Cross-site scripting (XSS) vulnerabilities allow attackers to inject malicious scripts into web pages viewed by other users.