CVE-2025-66563

Monkeytype is a minimalistic and customizable typing test. In 25.49.0 and earlier, there is improper handling of user input which allows an attacker to execute malicious javascript on anyone viewing a malicious quote submission. quote.text and quote.source are user input, and they're inserted straight into the DOM. If they contain HTML tags, they will be rendered (after some escaping using quotes and textarea tags).

Score

CVSS 4.0 7.1 High

Status

Analyzed - security-advisories@github.com

Published

2025-12-04

Last modified

2026-10-18

Weaknesses

CWE-79

Affected products

• Monkeytype (Monkeytype)
• Monkeytype (Monkeytypegame)

References

• https://github.com/monkeytypegame/monkeytype/security/advisories/GHSA-mfjh-9552-8g27
• https://github.com/monkeytypegame/monkeytype/commit/d6d062a77132ba7d6ba3b482d46ae329d3b8d695