CVE-2026-21710
- State
- Published
- Severity
- 7.5 High
- Published
- Mar 30, 2026
- Updated
- Jul 15, 2026
- Reserved
- Jan 4, 2026
Description
A flaw in Node.js HTTP request handling causes an uncaught `TypeError` when a request is received with a header named `__proto__` and the application accesses `req.headersDistinct`.
When this occurs, `dest["__proto__"]` resolves to `Object.prototype` rather than `undefined`, causing `.push()` to be called on a non-array. This exception is thrown synchronously inside a property getter and cannot be intercepted by `error` event listeners, meaning it cannot be handled without wrapping every `req.headersDistinct` access in a `try/catch`.
* This vulnerability affects all Node.js HTTP servers on **20.x, 22.x, 24.x, and v25.x**
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.0 | 7.5 High | CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | hackerone |
| 3.1 | 7.5 High | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | redhat-SADP |
Weaknesses
Affected Products
| Product | Versions |
|---|---|
nodenodejs |
|
References
- https://nodejs.org/en/blog/vulnerability/march-2026-security-releases
- https://access.redhat.com/security/cve/CVE-2026-21710vdb-entry
- RHBZ#2453151issue-tracking
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-21710.json
- https://access.redhat.com/errata/RHSA-2026:7310vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:7080vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:7675vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:8339vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:7123vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:7670vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:9711vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:9874vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:7983vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:7896vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:7302vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:7350vendor-advisory
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