CVE-2025-66563: Monkeytype vulnerable to stored XSS in approve quotes page

Published Dec 4, 2025
·
Updated

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 Software

2 affected components
Monkeytype Monkeytype<25.49.0
Monkeytype Monkeytype<=25.49.0

Event History

Dec 4, 2025
CVE Published
via MITRE·10:34 PM
Data Sourced
via MITRE·10:34 PM
DescriptionWeakness
Data Sourced
via NVD·11:15 PM
RemedyDescriptionSeverityWeaknessAffected Software
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Frequently Asked Questions

1

What is the severity of CVE-2025-66563?

The severity of CVE-2025-66563 is rated as high due to the potential for remote code execution via injected JavaScript.

2

How do I fix CVE-2025-66563?

To fix CVE-2025-66563, upgrade to Monkeytype version 25.49.1 or later that addresses the input validation issue.

3

What kind of attack does CVE-2025-66563 enable?

CVE-2025-66563 enables cross-site scripting (XSS) attacks through improper handling of user input in quote submissions.

4

Who is affected by CVE-2025-66563?

Users of Monkeytype version 25.49.0 and earlier are affected by CVE-2025-66563.

5

What are the user input fields involved in CVE-2025-66563?

The user input fields involved in CVE-2025-66563 are quote.text and quote.source.

Contact

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