Misskey

Misskey is an open source, federated social media platform. Versions 12.37.0 and later, but prior to 2026.5.4, contain a vulnerability in the JSON-LD signature validation and compaction process that allows spoofed activities to be accepted as valid. This issue has been fixed in version 2026.5.4.

Published: 2026-08-03T21:37:45.657Z
Updated: 2026-08-04T15:44:53.013Z

Misskey is an open source, federated social media platform. Versions 2025.3.2 and later, but prior to 2026.5.4, contain a vulnerability where a lack of proper permission checks allows access to certain data points from the Direct Messages (formerly Chat) feature, regardless of account permissions. This vulnerability occurs whether or not federation is enabled. Notes created with "specified" visibility (formerly "direct" visibility) are not affected. This issue has been fixed in version 2026.5.4.

Published: 2026-08-03T21:29:49.394Z
Updated: 2026-08-04T15:55:04.271Z

Misskey is an open source, federated social media platform. IVersions 8.63.0 and later, but prior to 2026.5.4, contain a vulnerability that can cause the Misskey web client to slow down or crash when it applies a malformed theme. This issue has been fixed in version 2026.5.4.

Published: 2026-08-03T21:58:36.825Z
Updated: 2026-08-05T14:27:42.341Z

Misskey is an open source, federated social media platform. Versions 12.37.0 and later, but prior to 2026.5.4, are vulnerable to timing attacks during JSON-LD signature validation and the compaction process. Because the JSON-LD parsing context is not shared between signature verification and subsequent processing, the application may trust information that should not be trusted, resulting in a time-of-check to time-of-use (TOCTOU) flaw. This allows an attacker to have fraudulent activities accepted as valid, leading to a loss of integrity. This issue has been fixed in version 2026.5.4.

Published: 2026-08-03T21:56:40.198Z
Updated: 2026-08-04T14:11:19.206Z

Misskey is an open source, federated social media platform. All Misskey servers running versions 2024.5.0 and later, but prior to 2026.5.4, contain a vulnerability in the Server Announcements API where insufficient permission checks allow attackers to access limited portions of data that they normally couldn't view. This vulnerability occurs whether or not federation is enabled. This issue has been fixed in version 2026.5.4.

Published: 2026-08-03T21:21:59.281Z
Updated: 2026-08-05T14:24:48.433Z