LiquidJS versions before 10.25.3 perform path-based checks for template inclusion directives ({% include %}, {% render %}, {% layout %}) to ensure files are within configured partials or layouts roots. However, these checks do not resolve symbolic links (realpath), allowing a symlink inside the allowed root to point to a file outside it. When LiquidJS opens the file, it follows the symlink and renders the external file, bypassing directory restrictions. This can be exploited in environments where attackers can place or influence template files under trusted roots, such as uploaded themes or repository-controlled templates. The vulnerability is tracked as CWE-61 (Improper Restriction of Symbolic Links).

An attacker with the ability to place or influence template files within allowed directories can cause LiquidJS to render arbitrary files outside those directories by leveraging symbolic links. This may lead to unauthorized disclosure of sensitive files or unintended template rendering. The CVSS 4.0 score is 8.2 (high severity), indicating network attack vector, low attack complexity, no privileges required, no user interaction, but high impact on confidentiality. No known exploits in the wild are reported.

The vulnerability is fixed in LiquidJS version 10.25.3. Users should upgrade to version 10.25.3 or later to resolve this issue. Since no official vendor advisory or patch link is provided, verify the upgrade from the official project repository or release notes. Until upgraded, restrict the ability of untrusted users to place or modify template files or symbolic links under the trusted template roots to mitigate exploitation risk.