Vulnerabilities in pkg:npm/@builder.io/qwik

PACKAGE
Advisory Identifier: GHSA-x586-xvc8-g7q6
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Advisory Summary

CVE-2026-84994 is a HIGH remote code execution vulnerability (CWE-248: Uncaught Exception) affecting Qwik libraries in the npm ecosystem. The issue involves crashing any qwik server via resource thenable. Remediation is available by upgrading affected packages to version 1.20.0, 2.0.0-beta37.

5 Known Advisory Record(s)
Package Vulnerability Intelligence

pkg:npm/@builder.io/qwik

5 Known Advisory Record(s)

Vulnerability advisories affecting package pkg:npm/@builder.io/qwik. Select an advisory below to view technical details or fixes.

Advisory ID CVE / NVD Severity Summary
GHSA-x586-xvc8-g7q6 CVE-2026-84994 HIGH Qwik: Crashing any Qwik Server via Resource thenable
GHSA-p9x5-jp3h-96mm CVE-2026-27971 CRITICAL Qwik vulnerable to Unauthenticated RCE via server$ Deserialization
GHSA-2rwj-7xq8-4gx4 CVE-2024-41677 MODERATE Qwik has a potential mXSS vulnerability due to improper HTML escaping
GHSA-9wf9-qvvp-2929 CVE-2023-1283 CRITICAL builderio/qwik is vulnerable to code injection
GHSA-hm7f-rq7q-j9xp CVE-2023-0410 MODERATE @builder.io/qwik vulnerable to Cross-site Scripting

CVE-2026-84994 at a Glance

CVE Identifier CVE-2026-84994
GHSA Identifier GHSA-x586-xvc8-g7q6
Severity HIGH
CVSS v3.1 Base Score N/A
CWE Classification CWE-248: Uncaught Exception
Affected Product Qwik
Package Ecosystem npm
Published Date
Last Updated

How to Fix CVE-2026-84994

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

@builder.io/qwik fixed: 1.20.0 
npm install @builder.io/qwik@1.20.0
@qwik.dev/core fixed: 2.0.0-beta37 
npm install @qwik.dev/core@2.0.0-beta37
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 @builder.io/qwik

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2026-84994, inspect your project dependencies using npm:

npm ls @builder.io/qwik

Analyze the terminal output to locate any version of Qwik in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.20.0), your application is affected.

Note: The npm ls @builder.io/qwik 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-248: Uncaught Exception, where an exception is thrown from a function, but it is not caught. In Qwik, 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

### Summary A Qwik server in the default configuration can be crashed with one unauthenticated HTTP request. During qwik-json body parsing, `ResourceSerializer.$fill$` does `Promise.resolve(resource._resolved)`. If `_resolved` is a plain object whose `.then` is a QRL for an unregistered symbol, the async QRL rejects, the rejection is orphaned, and Node terminates the process via its default unhandled-rejection policy. ### Impact One unauthenticated request crashes the server. Looping keeps every replica dead as long as the attacker sends requests.

CVE-2026-84994 Affected Qwik Versions

2 component(s)
Fixed Versions:
1.20.02.0.0-beta37
Product / Package Ecosystem Affected Versions Fixed Version
@builder.io/qwik
npm/@builder.io/qwik
npm
< 1.20.0
1.20.0
@qwik.dev/core
npm/@qwik.dev/core
npm
< 2.0.0-beta37
2.0.0-beta37

References

GitHub Advisory / Wiki ADVISORY
https://github.com/QwikDev/qwik/security/advisories/GHSA-x586-xvc8-g7q6
NVD — CVE-2026-84994 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-84994
Qwik Source Repository REPOSITORY
https://github.com/QwikDev/qwik/pull/8655
Security Fix Commit FIX COMMIT
https://github.com/QwikDev/qwik/commit/c1e7444402f9592b5cf9096e10bf303ab4640511
Qwik Source Repository REPOSITORY
https://github.com/QwikDev/qwik
Qwik Release RELEASE
https://github.com/QwikDev/qwik/releases/tag/@builder.io/qwik@1.20.0

Frequently Asked Questions

What is CVE-2026-84994?
CVE-2026-84994 is a security vulnerability in Qwik involving Crashing any Qwik Server via Resource thenable under CWE-248: Uncaught Exception.
Which Qwik versions are affected?
Affected versions include releases prior to 1.20.0, 2.0.0-beta37 across affected packages: @builder.io/qwik, @qwik.dev/core.
What version fixes CVE-2026-84994?
Upgrading to 1.20.0, 2.0.0-beta37 (or the latest patched release for your respective branch) resolves the vulnerability.
Is @builder.io/qwik affected?
Yes, @builder.io/qwik is affected in releases prior to 1.20.0. Upgrade your dependency to 1.20.0 or later.
Is @qwik.dev/core affected?
Yes, @qwik.dev/core is affected in releases prior to 2.0.0-beta37. Upgrade your dependency to 2.0.0-beta37 or later.
What CWE is associated with CVE-2026-84994?
CVE-2026-84994 is classified under CWE-248: Uncaught Exception (An exception is thrown from a function, but it is not caught.).
How can I check npm dependencies for CVE-2026-84994?
Run the dependency tree command: 'npm ls @builder.io/qwik'. 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-x586-xvc8-g7q6",
  "modified" : "2026-10-15T20:22:00Z",
  "published" : "2026-10-15T20:22:00Z",
  "aliases" : [ "CVE-2026-84994" ],
  "summary" : "Qwik: Crashing any Qwik Server via Resource thenable",
  "details" : "### Summary\n\nA Qwik server in the default configuration can be crashed with one unauthenticated HTTP request. During qwik-json body parsing, `ResourceSerializer.$fill$` does `Promise.resolve(resource._resolved)`. If `_resolved` is a plain object whose `.then` is a QRL for an unregistered symbol, the async QRL rejects, the rejection is orphaned, and Node terminates the process via its default unhandled-rejection policy.\n\n### Impact\n\nOne unauthenticated request crashes the server. Looping keeps every replica dead as long as the attacker sends requests.",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "@builder.io/qwik"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.20.0"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "npm",
      "name" : "@qwik.dev/core"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "2.0.0-beta37"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/QwikDev/qwik/security/advisories/GHSA-x586-xvc8-g7q6"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-84994"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/QwikDev/qwik/pull/8655"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/QwikDev/qwik/commit/c1e7444402f9592b5cf9096e10bf303ab4640511"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/QwikDev/qwik"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/QwikDev/qwik/releases/tag/@builder.io/qwik@1.20.0"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-248" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-10-15T20:22:00Z",
    "nvd_published_at" : "2026-10-13T19:20:52Z"
  }
}