EUVD-2026-99978Published

Qwik: Crashing any Qwik Server via Resource thenable

Collected exploitation and prediction evidence

CISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.

No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.

cve-program · CVE-2026-84994

Published

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.

Source published: 13 Oct 2026 19:00:53 UTC
Source modified: 14 Oct 2026 16:36:19 UTC
Observed here: 23 Oct 2026 15:48:27 UTC
Source terms: CVE Program Terms of Use

Original source record · Cite this exact observation · Complete original publisher JSON

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CVSS 4.0 · 8.7 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

euvd · EUVD-2026-99978

Published

EUVD source date text has no stated timezone and is retained without inventing a UTC instant. Related bulletin membership is not an alias, common cause or applicability claim. A missing vector with a zero score is treated as unrated. Complete vendor/product and underlying source evidence remains in the original JSON.

Original publisher date fields

datePublished: Oct 13, 2026, 7:00:53 PM

dateUpdated: Oct 14, 2026, 4:36:19 PM

Source published: Oct 13, 2026, 7:00:53 PM (timezone not stated)
Source modified: Oct 14, 2026, 4:36:19 PM (timezone not stated)
Observed here: 7 Nov 2026 15:22:28 UTC
Source terms: ENISA EUVD · source terms and attribution apply

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: euvd · ENISA EUVD · source terms and attribution apply. Source text is retained; field grouping and change labels are provided by ChangeIntel.

EUVD CVSS 4.0 · 8.7 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

nvd · CVE-2026-84994

Published

NVD analysis and CPE criteria are source context, not proof that a package or your environment is affected. Complete affected data, logical configurations and SSVC are retained in the original JSON.

Source analysis status: Awaiting Analysis

Weakness classifications: CWE-248

Original publisher date fields

published: 2026-10-13T19:20:52.743

lastModified: 2026-10-14T17:19:46.043

Source published: 13 Oct 2026 19:20:52 UTC
Source modified: 14 Oct 2026 17:19:46 UTC
Observed here: 25 Oct 2026 16:19:16 UTC
Source terms: NIST NVD usage terms; underlying source attribution retained

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: nvd · NIST NVD usage terms; underlying source attribution retained. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 4.0 · [email protected] · Secondary · 8.7 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

osv · GHSA-x586-xvc8-g7q6

Published

### 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.

Source published: 15 Oct 2026 20:22:00 UTC
Source modified: 15 Oct 2026 20:30:03 UTC
Observed here: 24 Oct 2026 13:17:17 UTC
Source terms: GitHub Advisory Database · CC-BY-4.0

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V4 · 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

Publisher rating · HIGH