CVE-2025-59838 Monkeytype Vulnerable to Self-XSS on loading saved custom text
An attacker can execute arbitrary scripts in a victim's browser by tricking them into loading a malicious saved custom text in Monkeytype.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2025-59838?
CVE-2025-59838 is a low-severity cross-site scripting vulnerability in monkeytypegame monkeytype, published on 25 Sep 2025. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
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.
Weakness: CWE-79
Which versions are affected by CVE-2025-59838?
It affects 1 product.
Products include Monkeytype Monkeytype.
How do I fix CVE-2025-59838?
No fix has been published for CVE-2025-59838 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2025-59838 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-59838 exists.
Other vulnerabilities in monkeytypegame monkeytype
Sources
Also known as GHSA-j4xx-fww5-774w.