Vulnerability · Published Dec 4, 2025 · Assigned by GitHub_M
CVE-2025-66563Monkeytype vulnerable to stored XSS in approve quotes page
High 7.1
In plain English
A high-severity cross-site scripting in monkeytype from monkeytypegame. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 17% of all known vulnerabilities).
Official description
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).
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| monkeytypegame | monkeytype | <= 25.49.0 |
Weakness: CWE-79 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N