CVE-2026-84994

Qwik: Crashing any Qwik Server via Resource thenable

HIGH
8.7
CVSS Score
Published: October 13, 2026 at 07:00 PM UTC
Updated: October 14, 2026 at 05:19 PM UTC
2 products affected across 2 vendorsQwikQwik

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Severity
HIGH8.7
Exploit prediction
EPSS 0.5%
SSVC
No known exploit

Description

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 1.20.0
v < 2.0.0-beta37

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

8.7HIGHGitHub_M
Vector?

Quick Info

StatusAWAITING ANALYSIS
CWE
CWE-248

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