Misskey allows token to remain valid in cookie after signing out

Vulnerability Description

Misskey is an open source, federated social media platform. Starting in version 12.109.0 and prior to version 2025.2.0-alpha.0, a login token named `token` is stored in a cookie for authentication purposes in Bull Dashboard, but this remains undeleted even after logout is performed. The primary affected users will be users who have logged into Misskey using a public PC or someone else's device, but it's possible that users who have logged out of Misskey before lending their PC to someone else could also be affected. Version 2025.2.0-alpha.0 contains a fix for this issue.

References

• https://github.com/misskey-dev/misskey/security/advisories/GHSA-w98m-j6hq-cwjm
• https://github.com/misskey-dev/misskey/commit/ba9f295ef2bf31cc90fa587e20b9a7655b7a1824