Misskey is an open source, federated social media platform. Starting in version 12.109.0 and prior to version 2025.2.0-alpha.0, due to a lack of CSRF protection and the lack of proper security attributes in the authentication cookies of Bull's dashboard, some of the APIs of bull-board may be subject to CSRF attacks. There is a risk of this vulnerability being used for attacks with relatively large impact on availability and integrity, such as the ability to add arbitrary jobs. This vulnerability was fixed in 2025.2.0-alpha.0. As a workaround, block all access to the `/queue` directory with a web application firewall (WAF).

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.

Misskey is an open source, federated social media platform.In affected versions missing validation in `NoteCreateService.insertNote`, `ApPersonService.createPerson`, and `ApPersonService.updatePerson` allows an attacker to control the target of any "origin" links (such as the "view on remote instance" banner). Any HTTPS URL can be set, even if it belongs to a different domain than the note / user. Vulnerable Misskey instances will use the unverified URL for several clickable links, allowing an attacker to conduct phishing or other attacks against remote users. This issue has been addressed in version 2024.11.0-alpha.3. Users are advised to upgrade. There are no known workarounds for this vulnerability.

Misskey is an open source, federated social media platform. In affected versions missing validation in `ApInboxService.update` allows an attacker to modify the result of polls belonging to another user. No authentication is required, except for a valid signature from any actor on any remote instance. Vulnerable Misskey instances will accept spoofed updates for remote polls. Local polls are unaffected. This issue has been addressed in version 2024.11.0-alpha.3. Users are advised to upgrade. There are no known workarounds for this vulnerability.

Misskey is an open source, federated social media platform. In affected versions missing validation in `ApRequestService.signedGet` and `HttpRequestService.getActivityJson` allows an attacker to create fake user profiles and forged notes. The spoofed users will appear to be from a different instance than the one where they actually exist, and the forged notes will appear to be posted by a different user. Vulnerable Misskey instances will accept the spoofed objects as valid, allowing an attacker to impersonate other users and instances. The attacker retains full control of the spoofed user / note and can interact like a real account. This issue has been addressed in version 2024.11.0-alpha.3. Users are advised to upgrade. There are no known workarounds for this vulnerability.

Misskey is an open source, federated social media platform. In affected versions missing validation in `ApRequestService.signedGet` allows an attacker to create fake user profiles that appear to be from a different instance than the one where they actually exist. These profiles can be used to impersonate existing users from the target instance. Vulnerable Misskey instances will accept spoofed users as valid, allowing an attacker to impersonate users on another instance. Attackers have full control of the spoofed user and can post, renote, or otherwise interact like a real account. This issue has been addressed in version 2024.11.0-alpha.3. Users are advised to upgrade. There are no known workarounds for this vulnerability.

Misskey is an open source, federated social media platform. Some APIs using `HttpRequestService` do not properly check the target host. This vulnerability allows an attacker to send POST or GET requests to the internal server, which may result in a SSRF attack.It allows an attacker to send POST or GET requests (with some controllable URL parameters) to private IPs, enabling further attacks on internal servers. This issue has been addressed in version 2024.11.0-alpha.3. Users are advised to upgrade. There are no known workarounds for this vulnerability.

Misskey is an open source, federated social media platform. In affected versions FileServerService (media proxy) in github.com/misskey-dev/misskey 2024.10.1 or earlier did not detect proxy loops, which allows remote actors to execute a self-propagating reflected/amplified distributed denial-of-service via a maliciously crafted note. FileServerService.prototype.proxyHandler did not check incoming requests are not coming from another proxy server. An attacker can execute an amplified denial-of-service by sending a nested proxy request to the server and end the request with a malicious redirect back to another nested proxy request. Leading to unbounded recursion until the original request is timed out. This issue has been addressed in version 2024.11.0-alpha.3. Users are advised to upgrade. Users unable to upgrade may configure the reverse proxy to block requests to the proxy with an empty User-Agent header or one containing Misskey/. An attacker can not effectively modify the User-Agent…

Misskey is an open source, decentralized microblogging platform. Misskey doesn't perform proper normalization on the JSON structures of incoming signed ActivityPub activity objects before processing them, allowing threat actors to spoof the contents of signed activities and impersonate the authors of the original activities. This vulnerability is fixed in 2024.5.0.

Misskey is an open source, decentralized social media platform with ActivityPub support. Prior to version 2024.2.0, when fetching remote Activity Streams objects, Misskey doesn't check that the response from the remote server has a `Content-Type` header value of the Activity Streams media type, which allows a threat actor to upload a crafted Activity Streams document to a remote server and make a Misskey instance fetch it, if the remote server accepts arbitrary user uploads. The vulnerability allows a threat actor to impersonate and take over an account on a remote server that satisfies all of the following properties: allows the threat actor to register an account; accepts arbitrary user-uploaded documents and places them on the same domain as legitimate Activity Streams actors; and serves user-uploaded document in response to requests with an `Accept` header value of the Activity Streams media type. Version 2024.2.0 contains a patch for the issue.