What is CVE-2026-27971?

CVE-2026-27971 is a critical-severity vulnerability in Qwik, classified under Deserialization of Untrusted Data. CVSS score: 9.8/10. Published 2026-03-03.

How severe is CVE-2026-27971?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Is CVE-2026-27971 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Deserialization in Qwik

CVE-2026-27971

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.

Vulnerability class: Insecure Deserialization

EPSS: 0.054 (91.9th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Qwik
Qwikdev Qwik — versions < 1.19.1

Weakness classification (CWE)

CWE-502 — Deserialization of Untrusted Data

Public proof-of-concept exploits

Ghalendar/CVE-2026-27971_POC

References

security-advisories@github.com (x_refsource_CONFIRM, Vendor Advisory)

Frequently asked questions

What is CVE-2026-27971?: CVE-2026-27971 is a critical-severity vulnerability in Qwik, classified under Deserialization of Untrusted Data. CVSS score: 9.8/10. Published 2026-03-03.
How severe is CVE-2026-27971?: Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2026-27971 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.