SiYuan versions before v3.8.1 contain a server-side request forgery vulnerability in the http_request and web_fetch agent tools that perform DNS resolution only at guard time without validating the connect-time resolution. Attackers can use DNS rebinding to answer the guard resolution with a public IP and the connect resolution with a private or metadata IP, bypassing the SSRF defense to access cloud instance metadata and internal services.

SiYuan before v3.8.1 contains a path traversal vulnerability in the asset.upload MCP tool that accepts arbitrary absolute file paths without workspace boundary validation. Attackers can induce the AI Agent to upload sensitive files such as SSH keys or credentials from outside the workspace into the asset directory through prompt injection.

SiYuan before v3.8.0 interpolates secret placeholders into the destination URL parameter of the http_request MCP tool, allowing attackers to exfiltrate stored secrets. An MCP client can craft a request with an attacker-controlled URL containing secret placeholders to send plaintext secret values to any public host without confirmation.

SiYuan versions before v3.8.0 contain an incomplete path blocklist in the MCP file tool that fails to restrict access to sensitive workspace files protected by the HTTP API. Authenticated administrators can read plaintext publish-mode passwords from data/.siyuan/publishAccess.json and access other sensitive files like data/templates and data/snippets/conf.json.

SiYuan versions before v3.7.4 fail to validate that packageName matches the downloaded package content in bazaar install endpoints. Attackers with same-origin access can overwrite existing trusted plugins by supplying mismatched packageName and repoURL parameters, achieving persistence across application restarts.

SiYuan versions before v3.7.4 contain an arbitrary file deletion vulnerability in the /api/search/removeTemplate endpoint that accepts an unvalidated path parameter passed directly to os.RemoveAll. Authenticated admin attackers can supply absolute filesystem paths to recursively delete any file or directory the kernel process has permission to remove, anywhere on the host filesystem.

SiYuan before v3.7.4 fails to validate the packageName parameter in Bazaar install and uninstall endpoints, allowing authenticated administrators to perform path traversal via directory traversal sequences. Attackers with admin access can write arbitrary files to any location via install operations or recursively delete directories via uninstall operations by supplying crafted packageName values.

SiYuan through 3.7.3 contains a cross-site scripting vulnerability in the '((' block-reference autocomplete hint popup. In genHintItemHTML() (app/src/protyle/hint/extend.ts), a candidate block's name, alias, and memo fields are concatenated into the popup's HTML without escaping. An attacker who can set these metadata fields on a block can inject a self-firing payload (e.g. <img src=x onerror=...>) that executes automatically when a victim types '((' followed by a search term that surfaces the crafted block. Because SiYuan's Electron windows run with nodeIntegration enabled, contextIsolation disabled, and no CSP, the injected script gains require('child_process') access, allowing the XSS to escalate to arbitrary OS command execution.

SiYuan before v3.7.4 contains a cross-site scripting vulnerability in the file-tree picker's hover-tooltip generation (app/src/util/pathName.ts, getLeaf()/movePathTo()) used by the 'move/link to' path-selection dialogs, where document metadata fields (bookmark, alias, memo, and an alternate name field) are concatenated into the aria-label HTML attribute without escaping. A document crafted with a double quote in any of these fields breaks out of the attribute context and injects arbitrary HTML attributes including inline event handlers (e.g., onmouseover). Because every SiYuan Electron BrowserWindow runs with nodeIntegration:true, contextIsolation:false, and no CSP, the injected handler gains require('child_process') access, escalating the XSS to arbitrary OS command execution when a victim merely hovers over the malicious document entry in the path-picker dialog. Malicious documents reach victims via sharing, sync, or import.

SiYuan before v3.7.4 contains a server-side request forgery (SSRF) vulnerability in the isPrivateIP function in kernel/util/net.go, used by SSRFSafeDialer to enforce SSRF protection in SafeMode. The function only checks for loopback, link-local unicast, private, and unspecified addresses and does not recognize IPv6 transition addresses (NAT64 64:ff9b::/96, 6to4 2002::/16, Teredo 2001::/32) that embed private IPv4 destinations. When SafeMode is enabled, an authenticated attacker can bypass the SSRF guard via the network forward proxy, WebSocket proxy, or SSE proxy endpoints by supplying a URL whose hostname resolves to such a transition address, reaching internal services and cloud metadata endpoints (e.g., 169.254.169.254). Because the forward proxy returns the full response body, this is a full-read SSRF that can be used to steal instance credentials, reach internal services, and port-scan internal infrastructure.