CVE-2026-66012

EIP tracks 1 public exploit for CVE-2026-66012. PoCs published by Hunt-Benito.

AI-analyzed exploit summary Exploits a missing-authorization vulnerability (CWE-862) in SiYuan's MCP endpoint when the Publish server is enabled in anonymous mode. The exploit achieves unauthenticated administrator takeover and RCE by chaining MCP tool access, credential exfiltration, and plugin planting.

SiYuan before v3.7.2 contains a missing authorization vulnerability in the POST /mcp kernel endpoint, which is gated only by a general auth check (model.CheckAuth) with no admin-role or read-only enforcement. This exposes 31 MCP tools, including a file tool with list/read/write/delete/rename/copy actions across the entire workspace. When the Publish server is enabled in anonymous mode (Conf.Publish.Enable=true and Conf.Publish.Auth.Enable=false), the Publish reverse proxy attaches an anonymous RoleReader JWT to proxied requests, allowing a remote unauthenticated attacker to reach /mcp. The attacker can read conf/conf.json to extract accessAuthCode, api.token, and cookieKey in plaintext, write arbitrary files in the workspace, and plant a plugin into data/plugins/ that executes with nodeIntegration:true and no contextIsolation on the next desktop launch, leading to administrator takeover.