Concorde, formerly know as Nexkey, is a fork of the federated microblogging platform Misskey. Prior to version 12.25Q1.1, due to an improper implementation of the logout process, authentication credentials remain in cookies even after a user has explicitly logged out, which may allow an attacker to steal authentication tokens. This could have devastating consequences if a user with admin privileges is (or was) using a shared device. Users who have logged in on a shared device should go to Settings > Security and regenerate their login tokens. Version 12.25Q1.1 fixes the issue. As a workaround, clear cookies and site data in the browser after logging out.

Concorde, formerly know as Nexkey, is a fork of the federated microblogging platform Misskey. Due to a lack of CSRF countermeasures and improper settings of cookies for MediaProxy authentication, there is a vulnerability that allows MediaProxy authentication to be bypassed. In versions prior to 12.25Q1.1, the authentication cookie does not have the SameSite attribute. This allows an attacker to bypass MediaProxy authentication and load any image without restrictions under certain circumstances. In versions prior to 12.24Q2.3, this cookie was also used to authenticate the job queue management page (bull-board), so bull-board authentication is also bypassed. This may enable attacks that have a significant impact on availability and integrity. The affected versions are too old to be covered by this advisory, but the maintainers of Concorde strongly recommend not using older versions. Version 12.25Q1.1 contains a patch. There is no effective workaround other than updating.

Altair is a fork of Misskey v12. Affected versions lack of request validation and lack of authentication in the image proxy for compressing and resizing remote files could allow attacks that could affect availability, such as by abnormally increasing the CPU usage of the server on which this software is running or placing a heavy load on the network it is using. This issue has been fixed in v12.24Q4.1. Users are advised to upgrade. There are no known workarounds for this vulnerability.

Nexkey is a lightweight fork of Misskey v12 optimized for small to medium size servers. Prior to 12.23Q4.5, Nexkey allows external apps using tokens issued by administrators and moderators to call admin APIs. This allows malicious third-party apps to perform operations such as updating server settings, as well as compromise object storage and email server credentials. This issue has been patched in 12.23Q4.5.

nexkey is a microblogging platform. Insufficient validation of ActivityPub requests received in inbox could allow any user to impersonate another user in certain circumstances. This issue has been patched in version 12.122.2.

Nexkey is a fork of Misskey, an open source, decentralized social media platform. Prior to version 12.121.9, incomplete URL validation can allow users to bypass authentication for access to the job queue dashboard. Version 12.121.9 contains a fix for this issue. As a workaround, it may be possible to avoid this by blocking access using tools such as Cloudflare's WAF.