CVE-2026-84994
CVE-2026-84994 is a high-severity vulnerability with a CVSS 4.0 base score of 8.7. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-248.
Key facts
- Severity: High (CVSS 4.0 base score 8.7)
- EPSS exploit prediction: 1% (44th percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-248
- Published:
- Last modified:
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.
Frequently asked questions
- What is CVE-2026-84994?
- 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.
- How severe is CVE-2026-84994?
- CVE-2026-84994 has a CVSS 4.0 base score of 8.7, rated high severity.
- Is CVE-2026-84994 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (44th percentile), an estimate of the probability of exploitation in the next 30 days.
- How do I fix CVE-2026-84994?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- When was CVE-2026-84994 published?
- CVE-2026-84994 was published on 2026-10-13 and last updated on 2026-10-14.
References
- https://github.com/QwikDev/qwik/commit/c1e7444402f9592b5cf9096e10bf303ab4640511
- https://github.com/QwikDev/qwik/pull/8655
- https://github.com/QwikDev/qwik/releases/tag/@builder.io/[email protected]
- https://github.com/QwikDev/qwik/security/advisories/GHSA-x586-xvc8-g7q6
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