high8.7
CVE-2026-84994
Qwik: Crashing any Qwik Server via Resource thenable
Impact
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.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| npm | @builder.io/qwik | < 1.20.0 | 1.20.0 |
| npm | @qwik.dev/core | < 2.0.0-beta37 | 2.0.0-beta37 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-x586-xvc8-g7q6
- https://github.com/QwikDev/qwik/security/advisories/GHSA-x586-xvc8-g7q6
- https://nvd.nist.gov/vuln/detail/CVE-2026-84994
- https://github.com/QwikDev/qwik/pull/8655
- https://github.com/QwikDev/qwik/commit/c1e7444402f9592b5cf9096e10bf303ab4640511
- https://github.com/QwikDev/qwik/releases/tag/@builder.io/qwik@1.20.0