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

7.1HIGH

Key Information:

Vendor

Monkeytypegame

Status
Monkeytype
Vendor
CVE Published:
4 December 2025

What is 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).

Affected Version(s)

monkeytype <= 25.49.0

References

https://github.com/monkeytypegame/monkeytype/security/adv...
x_refsource_CONFIRM
https://github.com/monkeytypegame/monkeytype/commit/d6d06...
x_refsource_MISC

CVSS V4

Score:
7.1
Severity:
HIGH
Confidentiality:
High
Integrity:
Low
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
Unknown

Timeline

  • Vulnerability published

  • Vulnerability Reserved

JSON
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CVE-2025-66563 : Improper Input Handling in Monkeytype Typing Test Application