---
title: "CVE-2026-56850: nodejs node vulnerability"
url: https://erroneo.us/security/cve/CVE-2026-56850/
description: "CVE-2026-56850 (nodejs node): A flaw in Node.js HTTPS Agent connection reuse can cause PFX object-array key collisions, allowing mutual TLS (mTLS) client…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-07-30
date_modified: 2026-08-04
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-56850"
kev: false
cvss: 4.1
epss: 0.00084
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-56850: nodejs node vulnerability

**Signal:** Normal patch cycle. No exploitation signal; fix it in your next routine update if you are affected. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
- EPSS 0.1% , percentile 0: FIRST’s model estimates a 0.1% chance of exploitation activity in the next 30 days, higher than 0% of all scored CVEs (low). EPSS is a probability, not a verdict.
- Needs local access needed. Lower urgency for most teams unless an attacker could already run code on the machine.
- Editorial verdict: Patch this week. Node.js July 2026 Security Releases: HTTP/2 and 11 CVEs — Routine but real: upgrade every supported Node.js line this week, sooner if you terminate HTTP/2 in Node or rely on the Permission Model as a sandbox.

## What it is

A flaw in Node.js HTTPS Agent connection reuse can cause PFX object-array key collisions, allowing mutual TLS (mTLS) client identities to be reused across requests configured with different client certificates. This vulnerability affects Node.js 26.x, 24.x, and 22.x.

## Affected products (CVE record)

- nodejs node: 26.5.0 <= 26.5.0, 24.18.0 <= 24.18.0, 22.23.1 <= 22.23.1

## Severity

- hackerone CVSS 3.0: 4.1 `CVSS:3.0/AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:H/A:N`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation none , automatable no , technical impact partial .
- FIRST EPSS (model of 2026-10-21): 0.08% probability of exploitation activity in the next 30 days; percentile 0.

## Sources

- [CVE.org record CVE-2026-56850](https://www.cve.org/CVERecord?id=CVE-2026-56850)
- [NVD entry CVE-2026-56850](https://nvd.nist.gov/vuln/detail/CVE-2026-56850)
- [nodejs.org](https://nodejs.org/en/blog/vulnerability/july-2026-security-releases)

---
Source page: https://erroneo.us/security/cve/CVE-2026-56850/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt