Input validation error in Misskey - CVE-2025-46559
Published: April 28, 2026
Vulnerability identifier: #VU128337
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:A/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2025-46559
CWE-ID: CWE-20
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Misskey Development Division
Affected software:
Misskey
Misskey
Detailed vulnerability description
The vulnerability allows a remote user to access unintended endpoints and modify data.
The vulnerability exists due to improper input validation in the Mk:api function when processing user-supplied endpoint paths. A remote user can supply a path prefixed with ../ to access unintended endpoints and modify data.
User interaction is required to execute malicious AiScript code.
How to mitigate CVE-2025-46559
Install security update from vendor's website.