Cyber Posture

CVE-2026-27971

Critical

Published: 03 March 2026

Published
03 March 2026
Modified
05 March 2026
KEV Added
Patch
CVSS Score 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.2439 96.1th percentile
Risk Priority 34 60% EPSS · 20% KEV · 20% CVSS

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…

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request. Affects any deployment where require() is available at runtime. This vulnerability is fixed in 1.19.1.

Mitigating Controls (NIST 800-53 r5)AI

prevent

Directly remediates the unsafe deserialization vulnerability in Qwik <=1.19.0 by requiring timely patching to the fixed version 1.19.1.

prevent

Validates untrusted HTTP request inputs to the server$ RPC deserialization mechanism, preventing processing of malicious payloads that trigger RCE.

preventdetect

Monitors and controls network traffic to the Qwik server, blocking or alerting on HTTP requests exploiting the deserialization vulnerability.

Security SummaryAI

CVE-2026-27971 affects Qwik, a performance-focused JavaScript framework, specifically versions up to and including 1.19.0. The vulnerability stems from unsafe deserialization in the server$ RPC mechanism, enabling remote code execution (RCE). It impacts any deployment where the require() function is available at runtime, as documented under CWE-502 (Deserialization of Untrusted Data). The issue carries a CVSS v3.1 base score of 9.8 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H), indicating critical severity.

Any unauthenticated attacker can exploit this vulnerability over the network with low complexity by sending a single HTTP request. Successful exploitation allows arbitrary code execution on the server, potentially leading to full compromise including high confidentiality, integrity, and availability impacts.

The Qwik security advisory confirms the vulnerability is fixed in version 1.19.1. Administrators should upgrade to 1.19.1 or later to mitigate the issue. Additional details are available in the GitHub Security Advisory at https://github.com/QwikDev/qwik/security/advisories/GHSA-p9x5-jp3h-96mm.

Details

CWE(s)

Affected Products

qwik
qwik
≤ 1.19.1

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
Why these techniques?

The vulnerability enables unauthenticated remote code execution via a single HTTP request to a public-facing Qwik application, directly mapping to exploitation of public-facing applications.

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

References