Qwik is a performance focused javascript framework. Prior to version 1.19.0, a prototype pollution vulnerability exists in the formToObj() function within @builder.io/qwik-city middleware. The function processes form field names with dot notation (e.g., user.name) to create nested objects, but fails to sanitize dangerous property names like __proto__, constructor, and prototype. This allows unauthenticated attackers to pollute Object.prototype by sending crafted HTTP POST requests, potentially leading to privilege escalation, authentication bypass, or denial of service. This issue has been patched in version 1.19.0.
History

Tue, 03 Feb 2026 21:30:00 +0000

Type Values Removed Values Added
Description Qwik is a performance focused javascript framework. Prior to version 1.19.0, a prototype pollution vulnerability exists in the formToObj() function within @builder.io/qwik-city middleware. The function processes form field names with dot notation (e.g., user.name) to create nested objects, but fails to sanitize dangerous property names like __proto__, constructor, and prototype. This allows unauthenticated attackers to pollute Object.prototype by sending crafted HTTP POST requests, potentially leading to privilege escalation, authentication bypass, or denial of service. This issue has been patched in version 1.19.0.
Title Prototype Pollution via FormData Processing in Qwik City
Weaknesses CWE-1321
References
Metrics cvssV3_1

{'score': 9.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:L'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-02-03T21:12:50.417Z

Reserved: 2026-01-29T15:39:11.821Z

Link: CVE-2026-25150

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-02-03T22:16:30.690

Modified: 2026-02-03T22:16:30.690

Link: CVE-2026-25150

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.