How severe is GHSA-x586-xvc8-g7q6?

No CVSS score has been assigned to GHSA-x586-xvc8-g7q6 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by GHSA-x586-xvc8-g7q6?

GHSA-x586-xvc8-g7q6 affects the following packages: @builder.io/qwik (npm), @qwik.dev/core (npm). Ecosystems affected: npm.

How do I fix GHSA-x586-xvc8-g7q6?

Update @builder.io/qwik to 1.20.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-x586-xvc8-g7q6 is resolved across your whole dependency graph.

How do I detect GHSA-x586-xvc8-g7q6 in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @builder.io/qwik, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate GHSA-x586-xvc8-g7q6 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Is GHSA-x586-xvc8-g7q6 actively exploited in the wild?

No public exploit code has been indexed for GHSA-x586-xvc8-g7q6 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for GHSA-x586-xvc8-g7q6?

GHSA-x586-xvc8-g7q6 has an EPSS (Exploit Prediction Scoring System) score of 0.5%, placing it in the 44th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is GHSA-x586-xvc8-g7q6?

GHSA-x586-xvc8-g7q6 is classified as CWE-248 (CWE-248). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was GHSA-x586-xvc8-g7q6 published, and has it been updated?

GHSA-x586-xvc8-g7q6 was published on October 15, 2026 and was last updated on October 15, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

📦 npm

Not in CISA KEV

Qwik: Crashing any Qwik Server via Resource thenableGHSA-x586-xvc8-g7q6

Fix: QwikDev/qwik#8655

GHSA-x586-xvc8-g7q6 is a CWE-248 vulnerability in @builder.io/qwik. A fix is available for @builder.io/qwik — see the affected versions and patch details below.

Also known asCVE-2026-84994

Published

Oct 15, 2026

Updated

Oct 15, 2026

Affected

2 pkgs

Patched

2 / 2

Exploits

None indexed

Exploitation data as of Oct 22, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for GHSA-x586-xvc8-g7q6.

EPSS Exploitation Probability

via FIRST.org ↗

0.5%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs44th percentile — riskier than 44% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

2 pkgs affected

How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.

29other npm packages depend on this — each one inherits the vulnerability until it's patched upstream

@builder.io/qwiknpm

26Kdownloads / week

@qwik.dev/corenpm

4Kdownloads / week

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 Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`@builder.io/qwik`	all versions	1.20.0`npm install @builder.io/qwik@1.20.0`
📦npm	`@qwik.dev/core`	all versions	2.0.0-beta37`npm install @qwik.dev/core@2.0.0-beta37`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @builder.io/qwik, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update @builder.io/qwik to 1.20.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-x586-xvc8-g7q6 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Frequently Asked Questions

### 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.

O3 Security · Impact-Aware SCA

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