CVE-2026-21710
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…
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EPSS puts the probability of exploitation in the next 30 days at 25.0%, higher than 98% of all known CVEs. Patch or mitigate before the next change window.
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**
- CVSS 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 25.04% probability · 98th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-770, CWE-843
- Affected
- nodejs/node.js · redhat/enterprise linux · redhat/enterprise linux eus
- Source
- support@hackerone.com
References
- https://nodejs.org/en/blog/vulnerability/march-2026-security-releasesVendor Advisory
- https://access.redhat.com/errata/RHSA-2026:7080Third Party Advisory
- https://access.redhat.com/errata/RHSA-2026:7123Third Party Advisory
- https://access.redhat.com/errata/RHSA-2026:7302Third Party Advisory
- https://access.redhat.com/errata/RHSA-2026:7310Third Party Advisory
- https://access.redhat.com/errata/RHSA-2026:7350Third Party Advisory
- https://access.redhat.com/errata/RHSA-2026:7670Third Party Advisory
- https://access.redhat.com/errata/RHSA-2026:7675Third Party Advisory
- https://access.redhat.com/errata/RHSA-2026:7896Third Party Advisory
- https://access.redhat.com/errata/RHSA-2026:7983Third Party Advisory
- https://access.redhat.com/errata/RHSA-2026:8339Third Party Advisory
- https://access.redhat.com/errata/RHSA-2026:9711Third Party Advisory
- https://access.redhat.com/errata/RHSA-2026:9874Third Party Advisory
- https://access.redhat.com/security/cve/CVE-2026-21710Third Party Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2453151Issue Tracking
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-21710.jsonThird Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.