CVE-2026-57574
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.55%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 4.0
- 7.4 HIGHCVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:A/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 0.55% probability · 44th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-294
- Source
- security-advisories@github.com
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
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.