CVE-2026-45017: Python Liquid: Absolute paths escape filesystem loader search path

Synopsis

This is a path traversal vulnerability in Python Liquid, a Python engine for the Liquid template language. An unauthenticated attacker who controls template content can pass an absolute file path to the {% include %} or {% render %} tags, bypassing the FileSystemLoader search path restriction and causing the engine to read arbitrary files on the host. Successful exploitation exposes the contents of any file readable by the application process, including secrets, configuration files, and source code. HarborGuard tracks this advisory and will make a patched-image rebuild available the moment version 2.2.0 or a later fix is published upstream.

HarborGuard Coverage

Exploit Conditions

• Network reachabilityRequired

  The vulnerable template engine is reachable over the network, so an attacker must be able to submit or influence template content delivered to the application remotely.

• AuthenticationNot required

  No credentials are needed; the CVSS vector specifies PR:N, meaning any party that can supply template input can attempt exploitation.

• Victim interactionNot required

  No user action is required to trigger the vulnerability; the malicious template is processed automatically by the engine.

• Attack complexityDetail

  The base exploit is straightforward and condition-free (AC:L), though the CVSS vector notes an attack requirement of AT:P, meaning the attacker must have or obtain the ability to author or inject template content.

Blast Radius

• An attacker reads arbitrary files on the host filesystem, limited only to files accessible by the process running the Liquid engine.
• Targeted files can include application secrets, API keys, database credentials, and environment configuration files.
• Source code and internal template files within the application directory are exposed if the process has read access to them.