CVE-2025-59838
MediumCVSS 5.4Exploitation Probability (EPSS)
Low risk17th percentile - higher than 17% of all known CVEs
Summary
Monkeytype, a typing test application, has an XSS vulnerability due to improper handling of user input when loading a saved custom text. Affects versions 25.36.0 and prior; fixed in version 25.44.0.
Risk Assessment
An attacker can exploit this vulnerability to execute malicious scripts in the victim's browser, potentially leading to data theft or session hijacking.
Recommendation
Update Monkeytype to version 25.44.0 or later, which includes a fix for this vulnerability.
Other vulnerabilities in Monkeytype
See all- CVE-2026-69183High
Monkeytype 26.26.0 and earlier has a vulnerability in the rate-limit key generator that uses client-controlled cf-connecting-ip and x-forwarded-for headers before req.ip. An unauthenticated attacker can rotate these headers to bypass rate limits, allowing repeated requests to endpoints like forgotPasswordEmail and verificationEmail, causing mail bombing, exhausting Firebase/SMTP quotas, and evading brute-force protection.
- CVE-2025-66563Medium
Monkeytype in version 25.49.0 and earlier improperly handles user input, allowing an attacker to execute malicious JavaScript on anyone viewing a malicious quote submission. quote.text and quote.source are user input and are inserted straight into the DOM; if they contain HTML tags, they will be rendered (after some escaping using quotes and textarea tags).
Original NVD description (English source)
Monkeytype is a minimalistic and customizable typing test. In versions 25.36.0 and prior, improper handling of user input when loading a saved custom text results in XSS. This issue has been fixed in version 25.44.0.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS