CVE-2026-56850

mTLS identity confusion via PFX key collisions

Published Jul 30, 2026 · Updated Jul 30, 2026

Improper authentication in Node.js 22.x, 24.x, and 26.x allows local users to reuse unintended mTLS client identities. The HTTPS Agent serializes distinct PFX object arrays into identical connection-pool keys, allowing a socket authenticated with one certificate to serve a request configured with another. Exploitation requires high-privileged local control over requests sharing an Agent and authenticates the request as the wrong configured client.

CVSS severity4.1
Medium
EPSS probability0.08%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper authentication in Node.js 22.x, 24.x, and 26.x allows local users to reuse unintended mTLS client identities. The HTTPS Agent serializes distinct PFX object arrays into identical connection-pool keys, allowing a socket authenticated with one certificate to serve a request configured with another. Exploitation requires high-privileged local control over requests sharing an Agent and authenticates the request as the wrong configured client.

The record

CVE
CVE-2026-56850
Published
Jul 30, 2026
Updated
Jul 30, 2026
Vendor
Node.js
Product
Node.js
Classifications
CWE-287
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Jul 30, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 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.

  1. Affected versionversion=22.23.1 <=22.23.1
  2. Affected versionversion=24.18.0 <=24.18.0
  3. Affected versionversion=26.5.0 <=26.5.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

Node.js · Node.jsversion=22.23.1 <=22.23.1; version=24.18.0 <=24.18.0; version=26.5.0 <=26.5.0

Published CVSS scores

4.1HackerOneCVSS:3.0/AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:H/A:N
4.4NIST NVDCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-287Improper Authentication

Public exploit references

No public exploit references are available in this record.

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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