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Response snapshot Oct 27, 2026, 16:01 UTC

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VulnerabilityCVE-2026-44646

LiquidJS's `{% render %}` tag silently bypasses per-render `ownPropertyOnly:true` via `Context.spawn()`

`Context.spawn()` in liquidjs creates a child `Context` for the `{% render %}` tag but does not propagate the parent context's resolved `ownPropertyOnly` value. The new context re-derives `ownPropertyOnly` from `opts.

Published Updated

At a glance

Exploited
Not known
Severity
5.3 Medium (CVSS 3.1)
Chance of exploitation
Not estimated
Sources
1 source

What to do

GitHub lists first patched versions: liquidjs: 10.26.0. Confirm the affected range and upgrade guidance in the exact advisory.

Read GitHub-reviewed advisory GHSA-9x9p-qf8f-mvjg (opens a new tab)

What happened

## Summary

`Context.spawn()` in liquidjs creates a child `Context` for the `{% render %}` tag but does not propagate the parent context's resolved `ownPropertyOnly` value. The new context re-derives `ownPropertyOnly` from `opts.ownPropertyOnly` (the instance-level option), silently discarding any `RenderOptions.ownPropertyOnly` override that was supplied to `parseAndRender()`.

As a result, a developer who runs a Liquid instance with the backwards-compatible `ownPropertyOnly:false` and then locks down an untrusted render with `parseAndRender(..., { ownPropertyOnly: true })` still leaks prototype-chain properties from inside any `{% render %}` partial.

This is a distinct exploit surface from the previously identified array-filter variants (`where`, `reject`, `group_by`, `find`, `find_index`, `has`) — the underlying root cause in `Context.spawn()` is shared, but `{% render %}` is a separately reachable sink that needs no filter usage.

Continue reading

## Details

The bug is in `Context.spawn()`:

```ts // src/context/context.ts:105-114 public spawn (scope = {}) { return new Context(scope, this.opts, { sync: this.sync, globals: this.globals, strictVariables: this.strictVariables // { const { liquid, hash } = this const filepath = (yield renderFilePath(this['file'], ctx, liquid)) as string assert(filepath, () => `illegal file path "${filepath}"`)

const childCtx = ctx.spawn() // /tmp/render-poc/_user.liquid

node -e " const { Liquid } = require('./dist/liquid.node.js'); const liquid = new Liquid({ ownPropertyOnly: false, root: '/tmp/render-poc' });

class User { constructor(n){ this.name = n; } } User.prototype.passwordHash = 'bcrypt\$secret'; const u = new User('alice');

liquid.parseAndRender( 'Direct:[{{ user.passwordHash }}] Render:[{% render \"_user.liquid\", user: user %}]', { user: u }, { ownPropertyOnly: true } ).then(console.log); " ```

Verified output on liquidjs 10.25.7:

``` Direct:[] Render:[bcrypt$secret] ```

The top-level expression `{{ user.passwordHash }}` is correctly blocked by the per-render `ownPropertyOnly:true`, but the same expression inside the partial loaded by `{% render %}` returns the prototype-chain property — proof that `Context.spawn()` discarded the override.

## Impact

- **Information disclosure**: Any prototype-chain property of objects passed into a `{% render %}` partial — including secrets, hashes, internal state, framework-injected helpers — becomes readable from inside the partial template, even when the developer used the documented per-render lockdown.

- **Realistic threat model**: Applications that maintain `ownPropertyOnly:false` for backwards compatibility (or because their data layer relies on prototype methods) and lock down untrusted-template renders with `parseAndRender(..., { ownPropertyOnly:true })` are protected at the top level but silently exposed inside any partial.

User-controllable template content (CMS snippets, theme partials, email templates) that uses `{% render %}` becomes an info-leak primitive. - **Distinct from existing CVE-2022-25948**: the prior advisory only covered direct use of `ownPropertyOnly:false`; this is a failure of the documented mitigation (`ownPropertyOnly:true` per-render override), not a missing setting.

- **Distinct from the array-filter variant**: same `spawn()` root cause, but exploitable without invoking `where/reject/group_by/find/find_index/has` — only requires that the template uses `{% render %}` (a basic templating feature) and that one of the rendered values has prototype-chain properties.

## Recommended Fix

Propagate `ownPropertyOnly` (and any other security-relevant render options) inside `Context.spawn()`:

```ts // src/context/context.ts public spawn (scope = {}) { return new Context(scope, this.opts, { sync: this.sync, globals: this.globals, strictVariables: this.strictVariables, ownPropertyOnly: this.ownPropertyOnly // <-- propagate resolved per-render value }, { renderLimit: this.renderLimit, memoryLimit: this.memoryLimit }) } ```

Passing `this.ownPropertyOnly` (the resolved value, not `this.opts.ownPropertyOnly`) ensures any `RenderOptions.ownPropertyOnly` override flows into spawned child contexts. This single change closes both the `{% render %}` pathway documented here and the array-filter pathway tracked separately. A regression test should assert that a partial rendered via `{% render %}` honours `parseAndRender(..., { ownPropertyOnly: true })` against an object with prototype-chain properties.

Affected package ranges reported by GitHub: liquidjs: < 10.26.0

Scores and how they were measured

CVSS base severity

5.3

Version 3.1As of

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Measurement source (opens a new tab)

How bad it is if exploited. Not a prediction of exploitation or proof you are exposed.

EPSS probability

Not available

A model's estimate of exploitation in the next 30 days, not certainty or your own risk.

Related technology

Sources

  1. Primary source

    GitHub-reviewed advisory GHSA-9x9p-qf8f-mvjg (opens a new tab)

    The public advisory supplies the description, affected package/version ranges, and any listed CVSS metric. GitHub review is not local review.

    Published Checked

  2. Primary source

    GitHub public advisory API page (opens a new tab)

    The API page supplied GHSA-9x9p-qf8f-mvjg, its actual identifiers, source dates, and structured metrics.

    Published Date not suppliedChecked

Cite this record

For factual claims, cite the primary sources above; cite KEVWire for its compilation, dates, and classifications.

APA

KEVWire. (2026, October 27). LiquidJS's `{% render %}` tag silently bypasses per-render `ownPropertyOnly:true` via `Context.spawn()` (CVE-2026-44646). https://kevwire.com/record/CVE-2026-44646

MLA

"LiquidJS's `{% render %}` tag silently bypasses per-render `ownPropertyOnly:true` via `Context.spawn()` (CVE-2026-44646)." KEVWire, 27 Oct. 2026, kevwire.com/record/CVE-2026-44646.

Chicago

KEVWire. "LiquidJS's `{% render %}` tag silently bypasses per-render `ownPropertyOnly:true` via `Context.spawn()` (CVE-2026-44646)." Last modified October 27, 2026. https://kevwire.com/record/CVE-2026-44646.

Evidence summary (plain text)

LiquidJS's `{% render %}` tag silently bypasses per-render `ownPropertyOnly:true` via `Context.spawn()` (May 27, 2026).
`Context.spawn()` in liquidjs creates a child `Context` for the `{% render %}` tag but does not propagate the parent context's resolved `ownPropertyOnly` value. The new context re-derives `ownPropertyOnly` from `opts.ownPropertyOnly` (the instance-level option), silently discarding any `RenderOptions.ownPropertyOnly` override that was supplied to `parseAndRender()`. As a result, a developer who runs a Liquid instance with the backwards-compatible `ownPropertyOnly:false` and then locks down an untrusted render with `parseAndRender(..., { ownPropertyOnly: true })` still leaks prototype-chain properties from inside any `{% render %}` partial. This is a distinct exploit surface from the previously identified array-filter variants (`where`, `reject`, `group_by`, `find`, `find_index`, `has`) — the underlying root cause in `Context.spawn()` is shared, but `{% render %}` is a separately reachable sink that needs no filter usage.

The bug is in `Context.spawn()`:
CVSS 5.3 (version 3.1; evidence as of Oct 27, 2026; https://github.com/advisories/GHSA-9x9p-qf8f-mvjg).
Sources:
GitHub-reviewed advisory GHSA-9x9p-qf8f-mvjg: https://github.com/advisories/GHSA-9x9p-qf8f-mvjg
GitHub public advisory API page: https://api.github.com/advisories?type=reviewed&per_page=100&sort=updated&direction=desc
Record ID: CVE-2026-44646.
Record origin: Ingested record.
AI evidence: Not assessed.
Known exploitation: Not assessed.
Zero-day status: Not assessed. KEV membership alone does not establish zero-day status.
About this data

This record was ingested from a data source. Retrieved: Oct 27, 2026, 16:00 UTC. Ingestion is not an independent editorial investigation.

A CISA KEV listing documents known exploitation, not necessarily a zero-day; absence from the catalog does not prove a vulnerability has never been exploited.

Technology tags indicate possible relevance, not verified exposure. Confirm the affected product, version, and configuration against your own inventory; KEVWire does not scan your systems.

A personal reading checklist on this device, not verified remediation.

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