Description
Misskey is an open source, federated social media platform. Prior to 2026.6.0, Misskey contains a Server-Side Request Forgery (SSRF) vulnerability in URL preview functionality in UrlPreviewService. Due to missing network restrictions before establishing outbound connections, a remote attacker can cause the Misskey server to initiate HTTP requests to loopback, private, or link-local services. Because IP address validation takes place after the request has been sent and the process is subsequently rejected, no sensitive internal data is believed to be transmitted back or exposed to the attacker. This issue is fixed in version 2026.6.0.
Problem types
CWE-918: Server-Side Request Forgery (SSRF)
Product status
References
github.com/...isskey/security/advisories/GHSA-jvcx-f39m-5xrj
github.com/...ommit/1eac4ccf513a067b9f7b7d123057c09a389fccee
github.com/misskey-dev/misskey/releases/tag/2026.6.0