CVE-2026-57574

Description

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.

References

• https://github.com/misskey-dev/misskey/commit/00c6210a591db2b0be438740d05b82070fa68ac6
• https://github.com/misskey-dev/misskey/commit/d323fe00d04ac46ab0b4e66fce9169effaa8dfb7
• https://github.com/misskey-dev/misskey/releases/tag/2026.6.0
• https://github.com/misskey-dev/misskey/security/advisories/GHSA-2m5x-5mp6-6vpq