What’s Vulnerable › Vulnerabilities

CVE-2025-66402: misskey.js's export data contains private post data

• Severity: medium (CVSS 6.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2025-12-16 · updated 2026-10-14
• Weakness: CWE-862

Description

Misskey is an open source, federated social media platform. Starting in version 13.0.0-beta.16 and prior to version 2025.12.0, an actor who does not have permission to view favorites or clips can can export the posts and view the contents. Version 2025.12.0 fixes the issue.

Affected products

• misskey-dev misskey: from 13.1.0 before 2025.12.0; 13.0.0, 13.0.0-beta16, 13.0.0-beta21, 13.0.0-beta22, 13.0.0-beta23, 13.0.0-beta24 (+30) — fixed in 2025.12.0

How to fix

Upgrade to a fixed version: misskey-dev misskey 2025.12.0. Check the vendor advisory for mitigations.

References

• https://github.com/misskey-dev/misskey/commit/dc77d59f8712d3fe0b73cd4af2035133839cd57b
• https://github.com/misskey-dev/misskey/security/advisories/GHSA-496g-mmpw-j9x3
• https://github.com/misskey-dev/misskey/security/advisories/GHSA-496g-mmpw-j9x3

Get alerted when CVE-2025-66402 or the next vulnerability affects your stack