Misskey: >> Misskey >> 12.101.0 Security Vulnerabilities
Misskey is an open source, federated social media platform. Starting in version 12.0.0 and prior to version 2025.4.1, due to an oversight in the validation performed in `UrlPreviewService` and `MkUrlPreview`, it is possible for an attacker to inject arbitrary CSS into the `MkUrlPreview` component. `UrlPreviewService.wrap` falls back to returning the original URL if it's using a protocol that is likely to not be understood by Misskey, IE something other than `http` or `https`. This both can de-anonymize users and_allow further attacks in the client. Additionally, `MkUrlPreview` doesn't escape CSS when applying a `background-image` property, allowing an attacker to craft a URL that applies arbitrary styles to the preview element. Theoretically, an attacker can craft a CSS injection payload to create a fake error message that can deceive the user into giving away their credentials or similar sensitive information. Version 2025.4.1 contains a patch for the issue.
CVSS Score
7.2
EPSS Score
0.0
Published
2025-05-05
Misskey is an open source, federated social media platform. Starting in version 12.31.0 and prior to version 2025.4.1, missing validation in `Mk:api` allows malicious AiScript code to access additional endpoints that it isn't designed to have access to. The missing validation allows malicious AiScript code to prefix a URL with `../` to step out of the `/api` directory, thereby being able to make requests to other endpoints, such as `/files`, `/url`, and `/proxy`. Version 2025.4.1 fixes the issue.
CVSS Score
5.4
EPSS Score
0.0
Published
2025-05-05
Misskey is an open source, federated social media platform. The patch for CVE-2024-52591 did not sufficiently validate the relation between the `id` and `url` fields of ActivityPub objects. An attacker can forge an object where they claim authority in the `url` field even if the specific ActivityPub object type require authority in the `id` field. Version 2025.2.1 addresses the issue.
CVSS Score
9.3
EPSS Score
0.001
Published
2025-03-10
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.
CVSS Score
6.4
EPSS Score
0.001
Published
2024-12-18
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.
CVSS Score
9.3
EPSS Score
0.001
Published
2024-12-18
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.
CVSS Score
5.3
EPSS Score
0.001
Published
2024-12-18
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.
CVSS Score
5.3
EPSS Score
0.001
Published
2024-12-18
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.
CVSS Score
8.2
EPSS Score
0.003
Published
2024-06-03
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.
CVSS Score
7.1
EPSS Score
0.002
Published
2024-02-19
Misskey is an open source, decentralized social media platform. Third-party applications may be able to access some endpoints or Websocket APIs that are incorrectly specified as [kind](https://github.com/misskey-dev/misskey/blob/406b4bdbe79b5b0b68fcdcb3c4b6e419460a0258/packages/backend/src/server/api/endpoints.ts#L811) or [secure](https://github.com/misskey-dev/misskey/blob/406b4bdbe79b5b0b68fcdcb3c4b6e419460a0258/packages/backend/src/server/api/endpoints.ts#L805) without the user's permission and perform operations such as reading or adding non-public content. As a result, if the user who authenticated the application is an administrator, confidential information such as object storage secret keys and SMTP server passwords will be leaked, and general users can also create invitation codes without permission and leak non-public user information. This is patched in version [2023.12.1](https://github.com/misskey-dev/misskey/commit/c96bc36fedc804dc840ea791a9355d7df0748e64).
CVSS Score
9.0
EPSS Score
0.001
Published
2023-12-29
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