Remote process crash via __proto__ header
Published Mar 30, 2026 · Updated Mar 30, 2026
Denial of service in Node.js HTTP servers 20.x, 22.x, 24.x, and 25.x allows remote attackers to crash the process via a crafted header. The headersDistinct getter accumulates values in a plain object, so proto resolves to Object.prototype and receives an invalid push call. Application code must access req.headersDistinct; the resulting synchronous TypeError bypasses error event listeners and interrupts the service.
Summary
What happened
Denial of service in Node.js HTTP servers 20.x, 22.x, 24.x, and 25.x allows remote attackers to crash the process via a crafted header. The headersDistinct getter accumulates values in a plain object, so proto resolves to Object.prototype and receives an invalid push call. Application code must access req.headersDistinct; the resulting synchronous TypeError bypasses error event listeners and interrupts the service.
The record
- CVE
- CVE-2026-21710
- Published
- Mar 30, 2026
- Updated
- Mar 30, 2026
- Vendor
- Node.js
- Product
- Node.js
- Classifications
- CWE-843, CWE-770, T1499
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Mar 30, 2026CVE publishedPublication date reported by the CVE source.
- Mar 30, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=10.0 <10.*
- Affected versionversion=11.0 <11.*
- Affected versionversion=12.0 <12.*
- Affected versionversion=13.0 <13.*
- Affected versionversion=14.0 <14.*
- Affected versionversion=15.0 <15.*
- Affected versionversion=16.0 <16.*
- Affected versionversion=17.0 <17.*
- Affected versionversion=18.0 <18.*
- Affected versionversion=19.0 <19.*
- Affected versionversion=20.20.1 <=20.20.1
- Affected versionversion=22.22.1 <=22.22.1
- Affected versionversion=24.14.0 <=24.14.0
- Affected versionversion=25.8.1 <=25.8.1
- Affected versionversion=4.0 <4.*
- Affected versionversion=5.0 <5.*
- Affected versionversion=6.0 <6.*
- Affected versionversion=7.0 <7.*
- Affected versionversion=8.0 <8.*
- Affected versionversion=9.0 <9.*
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- open-flaw CVE-2026-21710 proof of conceptproof of concept · unverified
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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