# CVE-2026-27971: Qwik - RCE

> Live exploitation tracking for CVE-2026-27971 by the CrowdSec Live Exploit Tracker, built from real-world attack data crowdsourced from CrowdSec's global network.

Page: https://tracker.crowdsec.net/cves/CVE-2026-27971

## Key facts

- **Exploitation phase:** Limited Exploitation. The vulnerability is known but shows very limited attacker interest or exploitation activity.
- **CVSS score:** 9.2
- **Public exploit available:** Yes
- **Affected products:** QwikDev Qwik
- **Weaknesses:** CWE-502 (Deserialization of Untrusted Data)
- **Tags:** javascript, web_application

## 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.

## CrowdSec analysis

[CVE-2026-27971](https://euvd.enisa.europa.eu/vulnerability/CVE-2026-27971) is a critical remote code execution vulnerability in Qwik versions up to 1.19.0, stemming from unsafe deserialization in the server$ RPC mechanism. This flaw allows unauthenticated attackers to execute arbitrary code on affected servers with a single HTTP request, posing a severe risk to any deployment where require() is available at runtime. Exploitation could lead to full system compromise, making immediate patching to version 1.19.1 essential for security.

CrowdSec has been tracking this vulnerability and its exploits since 30th of March 2026.

CrowdSec network observations suggest that most exploitation of CVE-2026-27971 involves focused reconnaissance to identify viable targets. Attackers typically tailor their campaigns based on system exposure and configuration. It is unlikely that a given attack is accidental.
CrowdSec network telemetry also shows that exploitation of CVE-2026-27971 has significantly declined over the past week. Attack volumes are well below the long-term average, suggesting attackers are rapidly losing interest. The vulnerability appears to be falling out of active use across most threat landscapes.

Attackers exploit the Qwik server by sending crafted POST requests to the `/?qfunc=sync` endpoint with malicious JSON payloads, targeting the server$ deserialization mechanism to achieve unauthenticated remote code execution.

## Timeline

- 2026-03-03: CVE Published. CVE-2026-27971 is published to NVD.
- 2026-03-30: Rule Released. CrowdSec releases a rule to detect CVE-2026-27971 exploitation attempts against the CrowdSec Network.
- 2026-04-01: CrowdSec First Seen. CrowdSec observes in-the-wild exploitation of CVE-2026-27971 for the first time.

## 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

## Live exploitation data

The [Live Exploit Tracker page](https://tracker.crowdsec.net/cves/CVE-2026-27971) follows observed exploitation activity for CVE-2026-27971. [Request an API key](https://tracker.crowdsec.net/request-api-key) for full access to its exploitation timeline, attacking IP addresses and blocklists.