LiquidJS Path Traversal and Memory Issues

Path traversal via symlink in LiquidJS npm package allows authenticated template contributors to read arbitrary filesystem content outside configured template roots. The vulnerability affects applications where untrusted users can influence template directories (uploaded themes, extracted archives, repository-controlled templates). LiquidJS validates template paths using string-based directory containment checks but fails to resolve canonical filesystem paths before file access, enabling symlinks placed within allowed partials/layouts directories to reference external files. Publicly available exploit code exists. No EPSS score available, but impact is limited to information disclosure in specific deployment scenarios requiring attacker filesystem access.

Path traversal in liquidjs 10.25.0 allows local file disclosure when renderFile() or parseFile() receives absolute paths or traversal sequences, despite the root parameter being documented as a sandbox boundary. An attacker controlling template filenames passed to these APIs can read arbitrary files accessible to the Node.js process, such as /etc/hosts or sensitive configuration files. The vulnerability affects liquidjs versions prior to 10.25.5; a vendor-released patch is available. No public exploit code or active exploitation has been identified at the time of analysis.

The replace filter in LiquidJS (Node.js npm package) fails to correctly account for memory usage when memoryLimit is enabled, allowing remote attackers to bypass DoS protections with approximately 2,500x memory amplification by crafting templates where the replace operation produces quadratically larger output than the charged memory cost. Deployments with memoryLimit explicitly configured to protect against untrusted template input can suffer out-of-memory crashes; patch available in v10.25.3.