CVE-2026-35525

LiquidJS enforces partial and layout root restrictions using the resolved pathname string, but it does not resolve the canonical filesystem path before opening the file. A symlink placed inside an allowed partials or layouts directory can therefore point to a file outside that directory and still be loaded.

Details

For {% include %}, {% render %}, and {% layout %}, LiquidJS checks whether the candidate path is inside the configured partials or layouts roots before reading it. That check is path-based, not realpath-based.

Because of that, a file like partials/link.liquid passes the directory containment check as long as its pathname is under the allowed root. If link.liquid is actually a symlink to a file outside the allowed root, the filesystem follows the symlink when the file is opened and LiquidJS renders the external target.

So the restriction is applied to the path string that was requested, not to the file that is actually read.

This matters in environments where an attacker can place templates or otherwise influence files under a trusted template root, including uploaded themes, extracted archives, mounted content, or repository-controlled template trees.

PoC

const { Liquid } = require('liquidjs');
const fs = require('fs');

fs.rmSync('/tmp/liquid-root', { recursive: true, force: true });
fs.mkdirSync('/tmp/liquid-root', { recursive: true });

fs.writeFileSync('/tmp/secret-outside.liquid', 'SECRET_OUTSIDE');
fs.symlinkSync('/tmp/secret-outside.liquid', '/tmp/liquid-root/link.liquid');

const engine = new Liquid({ root: ['/tmp/liquid-root'] });

engine.parseAndRender('{% render "link.liquid" %}')
  .then(console.log);
// SECRET_OUTSIDE

If an attacker can place or influence symlinks under a trusted partials or layouts directory, they can make LiquidJS read and render files outside the intended template root. In practice this can expose arbitrary readable files reachable through symlink targets.

CVE-2026-35525 has a CVSS score of 7.5 (High). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (10.25.3); upgrading removes the vulnerable code path.

Kodem intelligence

1. What is CVE-2026-35525? CVE-2026-35525 is a high-severity security vulnerability in liquidjs (npm), affecting versions <= 10.25.2. It is fixed in 10.25.3.
2. How severe is CVE-2026-35525? CVE-2026-35525 has a CVSS score of 7.5 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of liquidjs are affected by CVE-2026-35525? liquidjs (npm) versions <= 10.25.2 is affected.
4. Is there a fix for CVE-2026-35525? Yes. CVE-2026-35525 is fixed in 10.25.3. Upgrade to this version or later.
5. Is CVE-2026-35525 exploitable, and should I be worried? Whether CVE-2026-35525 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2026-35525 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2026-35525? Upgrade liquidjs to 10.25.3 or later.