CVE-2025-46559 Misskey Directory Traversal Vulnerability in AiScript via `Mk:api`

Medium 5.4 Published 5 May 2025 Updated 5 May 2025

Attackers can use malicious AiScript to bypass API restrictions and access unauthorized endpoints like files or proxies via path traversal.

Exploited in the wild: Not known
Login needed: Any signed-in user
Attackable: Over the internet
Victim action needed: A user has to click or open something
Fix: None listed

What is CVE-2025-46559?

CVE-2025-46559 is a medium-severity path traversal vulnerability in misskey-dev misskey, published on 5 May 2025. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

Official description

Misskey is an open source, federated social media platform. Starting in version 12.31.0 and prior to version 2025.4.1, missing validation in `Mk:api` allows malicious AiScript code to access additional endpoints that it isn't designed to have access to. The missing validation allows malicious AiScript code to prefix a URL with `../` to step out of the `/api` directory, thereby being able to make requests to other endpoints, such as `/files`, `/url`, and `/proxy`. Version 2025.4.1 fixes the issue.

Weakness: CWE-22

Which versions are affected by CVE-2025-46559?

It affects 1 product.

Products include Misskey Misskey.

How do I fix CVE-2025-46559?

No fix has been published for CVE-2025-46559 yet. Limit exposure of the affected software until one is available.

Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.

Is CVE-2025-46559 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-46559 exists.

Sources

Also known as GHSA-gmq6-738q-vjp2.