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…
Does this matter?
EPSS puts the probability of exploitation in the next 30 days at 25.4%, 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
- 25.44% probability · 98th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-770, CWE-843
- Affected
- nodejs/node.js · redhat/enterprise linux · redhat/enterprise linux eus
- Source
- support@hackerone.com
EPSS 25.4% since 30 October 2026; no change recorded yet. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
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, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.