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CVE-2026-44646 harttle CVE debrief

CVE-2026-44646 is a medium-severity vulnerability in LiquidJS, a Shopify/GitHub Pages compatible template engine. The issue allows for a silent bypass of the `ownPropertyOnly` value in the `Context.spawn()` method, which is used in the `{% render %}` tag. This can lead to a leak of prototype-chain properties from inside any `{% render %}` partial. The vulnerability has been fixed in version 10.26.0. Developers who use LiquidJS should update to the latest version to prevent potential exploitation. This issue is distinct from previously identified array-filter variants, but shares the same underlying root cause in `Context.spawn()`. The `{% render %}` tag is a separately reachable sink that does not require filter usage.

Vendor
harttle
Product
liquidjs
CVSS
MEDIUM 5.3
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-17
Original CVE updated
2026-06-22
Advisory published
2026-06-17
Advisory updated
2026-06-22

Who should care

Developers who use LiquidJS in their applications, especially those who use the `{% render %}` tag, should be aware of this vulnerability. Updating to version 10.26.0 or later can prevent potential exploitation. This issue may be of particular interest to developers who use LiquidJS with untrusted render inputs.

Technical summary

The `Context.spawn()` method in LiquidJS creates a child context for the `{% render %}` tag but does not propagate the parent context's resolved `ownPropertyOnly` value. This results in a silent bypass, allowing prototype-chain properties to leak from inside any `{% render %}` partial. The new context re-derives `ownPropertyOnly` from `opts.ownPropertyOnly` (the instance-level option), silently discarding any `RenderOptions.ownPropertyOnly` override supplied to `parseAndRender()`. This issue has a CVSS score of 5.3 and is classified as medium severity.

Defensive priority

High

Recommended defensive actions

  • Update LiquidJS to version 10.26.0 or later
  • Review and update any custom templates that use the `{% render %}` tag
  • Ensure that `ownPropertyOnly` is set to `true` for untrusted render inputs
  • Monitor for any suspicious activity or errors related to LiquidJS
  • Consider implementing additional security measures, such as input validation and sanitization

Evidence notes

The information provided is based on the official CVE record and NVD detail. The vulnerability has been fixed in version 10.26.0, and developers are advised to update to the latest version. The issue is related to the `Context.spawn()` method and the `{% render %}` tag in LiquidJS.

Official resources

LiquidJS is a Shopify/GitHub Pages compatible template engine written in pure JavaScript. In versions 10.25.7 and below, Context.spawn() creates a child Context for the {% render %} tag but does not propagate the parent context's resolved