CVE-2026-66396

SiYuan is a knowledge management system that prior to version 3.7.0 had security vulnerabilities related to 8 ungated APIs that could modify configuration and SQL index. Users with a valid JWT token could access these APIs, leading to unauthorized changes to server state.

SiYuan is an open-source personal knowledge management system. Prior to 3.6.5, the fix for CVE-2026-30869 only added a denylist check but did not address the root cause – a redundant url.PathUnescape() call in serveExport(). An authenticated attacker can use double URL encoding to traverse directories and read arbitrary workspace files including the full SQLite database, kernel log, and all user documents.

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

SiYuan before v3.7.4 fails to set Content-Disposition and X-Content-Type-Options headers when serving arbitrary file assets, allowing stored cross-site scripting attacks. Authenticated attackers can upload HTML files as assets and execute scripts with full kernel API access when the workspace owner opens the asset link.

SiYuan before 3.7.4 registers Go net/http/pprof debug endpoints including heap and goroutine dumps without authentication when --mode flag is not set to exactly prod. Attackers can access /debug/pprof/heap and related endpoints to extract in-memory secrets including AccessAuthCode and AI provider API keys.

SiYuan kernel versions before 3.7.4 contain an improper restriction of excessive authentication attempts vulnerability in the CheckAuth() middleware. The middleware accepts the API token via an Authorization header or ?token= query parameter, and neither path is protected by CAPTCHA/lockout. An unauthenticated remote attacker can perform unlimited automated guesses of the API token, especially when a short or weak custom token is configured, and upon success gains full RoleAdministrator access enabling arbitrary file operations and SQL queries.

SiYuan versions before v3.7.4 contain a cross-site scripting vulnerability in the unicode2Emoji function that fails to sanitize codepoint branch output. Attackers can craft document icons with hex-encoded markup that executes in the renderer with Node integration enabled, achieving arbitrary code execution on the host system.

SiYuan before v3.7.4 stores attribute-view field names without HTML escaping and interpolates them directly into option elements via innerHTML in the sort menu. Attackers can inject markup by renaming a database field to execute arbitrary JavaScript when users open the sort menu, with Node integration enabled in the desktop client enabling code execution.

SiYuan versions before v3.7.4 fail to validate or escape the color field in attribute-view select options, allowing stored cross-site scripting through eight unescaped render sites. Attackers can inject event-handler attributes by including quotation marks in the color value, executing arbitrary JavaScript when viewing databases containing the malicious select field.

SiYuan before v3.7.4 improperly restricts excessive authentication attempts in the CheckAuth() middleware. The HTTP Basic Authentication branch, which guards nearly the entire /api/* surface, accepts the workspace access code as the Basic Auth password but never consults the CAPTCHA/lockout gate or increments the failure counter used by the cookie/session login path. This allows unauthenticated remote attackers to brute-force the admin access code with unlimited automated requests and obtain full RoleAdministrator access to the kernel. A secondary weakness exists because the access code is compared using a non-constant-time string comparison.