---
title: "CVE-2026-27971: Qwik vulnerable to Unauthenticated RCE via server$ Deserialization"
url: https://erroneo.us/security/cve/CVE-2026-27971/
description: "CVE-2026-27971 (@builder.io/qwik (npm)): Qwik is a performance focused javascript framework. qwik"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-03-03
date_modified: 2026-03-04
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-27971"
kev: false
cvss: 9.2
epss: 0.02948
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-27971: Qwik vulnerable to Unauthenticated RCE via server$ Deserialization

**Signal:** Critical and remotely reachable. No known exploitation yet, but it is network-reachable without credentials. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
- EPSS 2.9% , percentile 87: FIRST’s model estimates a 2.9% chance of exploitation activity in the next 30 days, higher than 87% of all scored CVEs (elevated). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
- Only applies if your dependency tree includes @builder.io/qwik (npm) <= 1.19.0, fixed in 1.19.1 . Check your lockfile, including transitive dependencies.

## What it is

Qwik is a performance focused javascript framework. qwik

## Affected packages

- npm `@builder.io/qwik` <= 1.19.0 → fixed: 1.19.1

## Affected products (CVE record)

- QwikDev qwik: < 1.19.1

## Severity

- GitHub_M CVSS 4.0: 9.2 `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`
- GitHub CVSS 4.0: 9.2 `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`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation none , automatable no , technical impact total .
- FIRST EPSS (model of 2026-10-21): 2.95% probability of exploitation activity in the next 30 days; percentile 87.

## Sources

- [GitHub Advisory GHSA-p9x5-jp3h-96mm](https://github.com/advisories/GHSA-p9x5-jp3h-96mm)
- [CVE.org record CVE-2026-27971](https://www.cve.org/CVERecord?id=CVE-2026-27971)
- [NVD entry CVE-2026-27971](https://nvd.nist.gov/vuln/detail/CVE-2026-27971)
- [github.com](https://github.com/QwikDev/qwik/security/advisories/GHSA-p9x5-jp3h-96mm)
- [github.com](https://github.com/QwikDev/qwik/releases/tag/%40builder.io%2Fqwik%401.19.1)

---
Source page: https://erroneo.us/security/cve/CVE-2026-27971/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt