CVE-2026-39859: LiquidJS `renderFile()` / `parseFile()` Bypass Configured Vulnerability

MODERATE
Advisory Identifier: GHSA-v273-448j-v4qj
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CWE-22
Published
Advisory Summary

CVE-2026-39859 is a MODERATE `renderfile()` / `parsefile()` bypass configured vulnerability (CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')) affecting LiquidJS libraries in the npm ecosystem. The issue involves `renderfile()` / `parsefile()` bypass configured `root` and allow arbitrary file read. Remediation is available by upgrading affected packages to version 10.25.5.

CVE-2026-39859 at a Glance

CVE Identifier CVE-2026-39859
GHSA Identifier GHSA-v273-448j-v4qj
Severity MODERATE
CVSS v3.1 Base Score N/A
CWE Classification CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Affected Product LiquidJS
Package Ecosystem npm
Published Date
Last Updated

How to Fix CVE-2026-39859

To remediate this vulnerability, upgrade all affected LiquidJS dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

liquidjs fixed: 10.25.5 
npm install liquidjs@10.25.5
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

npm ls liquidjs

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2026-39859, inspect your project dependencies using npm:

npm ls liquidjs

Analyze the terminal output to locate any version of LiquidJS in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 10.25.5), your application is affected.

Note: The npm ls liquidjs command inspects dependencies declared in your package.json and lockfile; it does not perform automated runtime dynamic scanning.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal'), where the product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory. In LiquidJS, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

`liquidjs` 10.25.0 documents `root` as constraining filenames passed to `renderFile()` and `parseFile()`, but top-level file loads do not enforce that boundary. The published npm package `liquidjs@10.25.0` on Linux 6.17.0 with Node v22.22.1. A `Liquid` instance configured with an empty temporary directory as `root` still returned the contents of `/etc/hosts` when `renderFile('/etc/hosts')` was called. I have not exhaustively checked older releases yet; 10.25.0 is the latest tested version. Root cause: - `src/parser/parser.ts:83-85` calls `loader.lookup(file, LookupType.Root, ...)` and then reads the returned file. - `src/fs/loader.ts:38` passes `type !== LookupType.Root` into `candidates()`. - For `LookupType.Root`, `enforceRoot` is false, so `src/fs/loader.ts:47-66` accepts resolved absolute paths and fallback results without any `contains()` check. This appears adjacent to the March 10, 2026 fix for CVE-2026-30952, which hardened `include` / `render` / `layout` but not the top-level file-loading APIs. Proof of concept: ```javascript const fs = require('fs'); const os = require('os'); const path = require('path'); const { Liquid } = require('liquidjs'); const safeRoot = fs.mkdtempSync(path.join(os.tmpdir(), 'liquidjs-safe-root-')); const engine = new Liquid({ root: [safeRoot], extname: '.liquid' }); engine.renderFile('/etc/hosts').then(console.log); ``` Expected result: a path outside `root` should be rejected. Actual result: `/etc/hosts` is rendered successfully. Impact: any application that treats `root` as a sandbox boundary and forwards attacker-controlled template names into `renderFile()` or `parseFile()` can disclose arbitrary local files readable by the server process. Suggested fix: apply the same containment checks used for partial/layout lookups to `LookupType.Root`, and reject absolute or fallback paths unless they remain within an allowed root. A regression test should verify that `renderFile('/etc/hosts')` fails when `root` points to an unrelated directory.

CVE-2026-39859 Affected LiquidJS Versions

1 component(s)
Fixed Versions:
10.25.5
Product / Package Ecosystem Affected Versions Fixed Version
liquidjs
npm/liquidjs
npm
< 10.25.5
10.25.5

References

GitHub Advisory / Wiki ADVISORY
https://github.com/harttle/liquidjs/security/advisories/GHSA-v273-448j-v4qj
NVD — CVE-2026-39859 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-39859
LiquidJS Source Repository REPOSITORY
https://github.com/harttle/liquidjs/pull/870
Security Fix Commit FIX COMMIT
https://github.com/harttle/liquidjs/commit/f41c1fc02fe901598f3328118b42b13bc6bc9b04
LiquidJS Source Repository REPOSITORY
https://github.com/harttle/liquidjs
LiquidJS Release RELEASE
https://github.com/harttle/liquidjs/releases/tag/v10.25.5

Frequently Asked Questions

What is CVE-2026-39859?
CVE-2026-39859 is a security vulnerability in LiquidJS involving `renderFile()` / `parseFile()` bypass configured `root` and allow arbitrary file read under CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal').
Which LiquidJS versions are affected?
Affected versions include releases prior to 10.25.5 across affected packages: liquidjs.
What version fixes CVE-2026-39859?
Upgrading to 10.25.5 (or the latest patched release for your respective branch) resolves the vulnerability.
Is liquidjs affected?
Yes, liquidjs is affected in releases prior to 10.25.5. Upgrade your dependency to 10.25.5 or later.
What CWE is associated with CVE-2026-39859?
CVE-2026-39859 is classified under CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') (The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.).
How can I check npm dependencies for CVE-2026-39859?
Run the dependency tree command: 'npm ls liquidjs'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-v273-448j-v4qj",
  "modified" : "2026-04-09T14:29:19Z",
  "published" : "2026-04-08T15:04:44Z",
  "aliases" : [ "CVE-2026-39859" ],
  "summary" : "LiquidJS: `renderFile()` / `parseFile()` bypass configured `root` and allow arbitrary file read",
  "details" : "`liquidjs` 10.25.0 documents `root` as constraining filenames passed to `renderFile()` and `parseFile()`, but top-level file loads do not enforce that boundary.\n\nThe published npm package `liquidjs@10.25.0` on Linux 6.17.0 with Node v22.22.1. A `Liquid` instance configured with an empty temporary directory as `root` still returned the contents of `/etc/hosts` when `renderFile('/etc/hosts')` was called. I have not exhaustively checked older releases yet; 10.25.0 is the latest tested version.\n\nRoot cause:\n- `src/parser/parser.ts:83-85` calls `loader.lookup(file, LookupType.Root, ...)` and then reads the returned file.\n- `src/fs/loader.ts:38` passes `type !== LookupType.Root` into `candidates()`.\n- For `LookupType.Root`, `enforceRoot` is false, so `src/fs/loader.ts:47-66` accepts resolved absolute paths and fallback results without any `contains()` check.\n\nThis appears adjacent to the March 10, 2026 fix for CVE-2026-30952, which hardened `include` / `render` / `layout` but not the top-level file-loading APIs.\n\nProof of concept:\n```javascript\nconst fs = require('fs');\nconst os = require('os');\nconst path = require('path');\nconst { Liquid } = require('liquidjs');\n\nconst safeRoot = fs.mkdtempSync(path.join(os.tmpdir(), 'liquidjs-safe-root-'));\nconst engine = new Liquid({ root: [safeRoot], extname: '.liquid' });\n\nengine.renderFile('/etc/hosts').then(console.log);\n```\n\nExpected result: a path outside `root` should be rejected.\nActual result: `/etc/hosts` is rendered successfully.\n\nImpact: any application that treats `root` as a sandbox boundary and forwards attacker-controlled template names into `renderFile()` or `parseFile()` can disclose arbitrary local files readable by the server process.\n\nSuggested fix: apply the same containment checks used for partial/layout lookups to `LookupType.Root`, and reject absolute or fallback paths unless they remain within an allowed root. A regression test should verify that `renderFile('/etc/hosts')` fails when `root` points to an unrelated directory.",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "liquidjs"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "10.25.5"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 10.25.4"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/harttle/liquidjs/security/advisories/GHSA-v273-448j-v4qj"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-39859"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/harttle/liquidjs/pull/870"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/harttle/liquidjs/commit/f41c1fc02fe901598f3328118b42b13bc6bc9b04"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/harttle/liquidjs"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/harttle/liquidjs/releases/tag/v10.25.5"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-22" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-04-08T15:04:44Z",
    "nvd_published_at" : "2026-04-08T20:16:26Z"
  }
}