CVE-2026-84994 json
Qwik: Crashing any Qwik Server via Resource thenable
published 2026-10-13 26 d ago modified 2026-10-15 24 d ago also GHSA-x586-xvc8-g7q6 , EUVD-2026-99978
- cvss
- 8.7
- version 4.0, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.5%
- EPSS 0.5% chance of exploitation in 30 days, percentile 44%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- npm @builder.io/qwik 1.20.0
- npm @qwik.dev/core 2.0.0-beta37
- github.com/QwikDev/qwik@c1e7444 commit
- github.com/QwikDev/qwik#8655 pull request
- github.com/QwikDev/qwik/releases/tag/@builder.io/qwik@1.20.0 release
CISA SSVC
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 25 d ago
Exploit prediction
0.52% chance of exploitation in the next 30 days, higher than 44% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 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 |
| CNA | 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/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 |
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 |
Affected products
- QwikDev qwik
- @builder.io qwik
Classification
- Weakness
-
- CWE-248 Uncaught Exception
References
-
github.com
/QwikDev/qwik/pull/8655
web
-
github.com
/QwikDev/qwik/commit/c1e7444402f9592b5cf9096e10bf303ab4640511
web
-
github.com
/QwikDev/qwik/security/advisories/GHSA-x586-xvc8-g7q6
web
-
github.com
/QwikDev/qwik/releases/tag/@builder.io/qwik@1.20.0
web
-
nvd.nist.gov
/vuln/detail/CVE-2026-84994
advisory
-
github.com
/QwikDev/qwik
package
Sources
- CVE List CVE-2026-84994
- GitHub Advisory GHSA-x586-xvc8-g7q6
- NVD CVE-2026-84994
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.