CVE-2026-21710
Node.js: Node.js: Denial of Service due to crafted HTTP `__proto__` header
Severity
ImportantRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · March 31, 2026
Updated · June 30, 2026
Description
A flaw was found in Node.js. A remote attacker can exploit this vulnerability by sending a specially crafted HTTP request that includes a header named __proto__. When a Node.js application processes this request and attempts to access distinct headers, it encounters an unhandled error, leading to an application crash. This can result in a Denial of Service (DoS), making the affected service unavailable to users.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
CVSS / CWE
CVSS 3.1 · 7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CWE-843 · Access of Resource Using Incompatible Type ('Type Confusion')