Resource exhaustion in Node.js Node
CVE-2026-21710
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**
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.250 (97.9th percentile), scored .
Moderate probability of exploitation in the next 30 days — watch for active exploitation reports. 98th percentile — 97.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.250 · newest: 0.250 · change: 0.000
Affected products
- Node.js Node — versions 20.20.1, 22.22.1, 24.14.0
- Node.js
- Red Hat Enterprise Linux — versions 10.0, 8.0, 9.0
- Red Hat Enterprise Linux Eus — versions 10.0, 9.4, 9.6
Weakness classification (CWE)
Public proof-of-concept exploits
References
- nodejs.org/en/blog/vulnerability/march-2026-security-releases (Vendor Advisory)
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c (Third Party Advisory)
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c (Third Party Advisory)
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c (Third Party Advisory)
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c (Third Party Advisory)
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c (Third Party Advisory)
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c (Third Party Advisory)
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c (Third Party Advisory)
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c (Third Party Advisory)
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c (Third Party Advisory)
Frequently asked questions
- What is CVE-2026-21710?
- CVE-2026-21710 is a high-severity vulnerability in Node.js Node, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 7.5/10. Published 2026-03-30.
- How severe is CVE-2026-21710?
- High severity. CVSS v3 base score is 7.5 out of 10.
- Is CVE-2026-21710 known to be exploited?
- 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.