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.
References (3)
Core 3
Core References
X_Refsource_Confirm x_refsource_confirm
https://github.com/misskey-dev/misskey/security/advisories/GHSA-jvcx-f39m-5xrj
X_Refsource_Misc x_refsource_misc
https://github.com/misskey-dev/misskey/commit/1eac4ccf513a067b9f7b7d123057c09a389fccee
X_Refsource_Misc x_refsource_misc
https://github.com/misskey-dev/misskey/releases/tag/2026.6.0
Scores
CVSS v4
6.9
EPSS
0.0035
EPSS Percentile
27.4%
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
yes
Technical Impact
partial
Details
CWE
CWE-918
Status
published
Products (1)
misskey-dev/misskey
< 2026.6.0
Published
Jul 10, 2026
Tracked Since
Jul 11, 2026