---
id: CVE-2026-84994
title: Qwik is a performance-focused JavaScript framework
summary: >-
  Qwik is a performance-focused JavaScript framework. Prior to @builder.io/qwik
  1.20.0 and @qwik.dev/core 2.0.0-beta.37, default server-side qwik-json
  deserialization causes ResourceSerializer.$fill$ to pass resource._resolved to
  Promise.r…
severity: none
cwe:
  - CWE-248
published: '2026-10-13'
updated: '2026-10-13'
sourceUpdated: '2026-10-13T19:27:44.137'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-84994'
references:
  - url: >-
      https://github.com/QwikDev/qwik/commit/c1e7444402f9592b5cf9096e10bf303ab4640511
    label: security-advisories@github.com
  - url: 'https://github.com/QwikDev/qwik/pull/8655'
    label: security-advisories@github.com
  - url: 'https://github.com/QwikDev/qwik/releases/tag/@builder.io/qwik@1.20.0'
    label: security-advisories@github.com
  - url: 'https://github.com/QwikDev/qwik/security/advisories/GHSA-x586-xvc8-g7q6'
    label: security-advisories@github.com
tags:
  - nvd
ingestedAt: '2026-10-13T19:43:29.150Z'
---

## Overview

Qwik is a performance-focused JavaScript framework. Prior to @builder.io/qwik 1.20.0 and @qwik.dev/core 2.0.0-beta.37, default server-side qwik-json deserialization causes ResourceSerializer.$fill$ to pass resource._resolved to Promise.resolve without first rejecting attacker-controlled thenables. An unauthenticated request can provide a plain object whose then property is a QRL for an unregistered symbol, causing an orphaned asynchronous rejection that terminates Node.js under its default unhandled-rejection policy. A single request can crash a server, and repeated requests can keep replicas unavailable. This issue is fixed in @builder.io/qwik 1.20.0 and @qwik.dev/core 2.0.0-beta.37.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.