CVE-2026-57574: Misskey-Dev Misskey

High severity, CVSS 7.4. EPSS: 0.6% chance of exploitation in the next 30 days.

Misskey is an open source, federated social media platform. Prior to 2026.6.0, Misskey contains a vulnerability in Time-based One-Time Password (TOTP) authentication in UserAuthService where insufficient validation of used tokens allows the reuse of a single-use code within its valid time step. If both credentials and a TOTP code are obtained concurrently, an attacker may reuse the code to perform unauthorized actions, potentially leading to account takeover. This issue is fixed in version 2026.6.0.

Affected products

• Misskey-Dev Misskey: before 2026.6.0 (fixed in 2026.6.0)

Published 2026-07-10. Last modified 2026-07-13.