CVE-2026-106072

nodejs: nodejs: Authentication bypass via non-canonical IPv4 hostname verification

Published Oct 23, 2026 CVSS 3.1 · 6.7 Medium EPSS < 1% KEV · Not listed
Description
A flaw in Node.js TLS hostname verification allows a certificate with only a DNS SAN to authenticate an IP endpoint when the client connects using a non-canonical IPv4 spelling, such as `0177.0.0.1`, `0x7f.0.0.1`, `2130706433` or `127.1`.

`tls.checkServerIdentity()` did not classify these hosts as IP addresses, but normalized them to their canonical form and matched the result against the certificate DNS names. A certificate containing `DNS:127.0.0.1` and no `IP Address:127.0.0.1` SAN was therefore accepted, while the same certificate is correctly rejected for `127.0.0.1`. Exploitation requires a certificate with a numeric DNS SAN issued by a CA trusted by the client, and a platform resolver that accepts these spellings, such as glibc.

This vulnerability affects Node.js **26.x**, **24.x**, and **22.x**.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
Title Non‑Canonical IPv4 Spelling Allows TLS Hostname Verification Bypass in Node.js nodejs: nodejs: Authentication bypass via non-canonical IPv4 hostname verification
References
Metrics threat_severity

None

cvssV3_1

{'score': 6.7, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:L'}

threat_severity

Moderate

Type Values Removed Values Added
First Time appeared Nodejs
Nodejs nodejs
Vendors & Products Nodejs
Nodejs nodejs
Type Values Removed Values Added
Title Non‑Canonical IPv4 Spelling Allows TLS Hostname Verification Bypass in Node.js
Type Values Removed Values Added
Description A flaw in Node.js TLS hostname verification allows a certificate with only a DNS SAN to authenticate an IP endpoint when the client connects using a non-canonical IPv4 spelling, such as `0177.0.0.1`, `0x7f.0.0.1`, `2130706433` or `127.1`. `tls.checkServerIdentity()` did not classify these hosts as IP addresses, but normalized them to their canonical form and matched the result against the certificate DNS names. A certificate containing `DNS:127.0.0.1` and no `IP Address:127.0.0.1` SAN was therefore accepted, while the same certificate is correctly rejected for `127.0.0.1`. Exploitation requires a certificate with a numeric DNS SAN issued by a CA trusted by the client, and a platform resolver that accepts these spellings, such as glibc. This vulnerability affects Node.js **26.x**, **24.x**, and **22.x**.
Weaknesses CWE-295
References
Metrics cvssV3_0

{'score': 6.7, 'vector': 'CVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:L'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
hackerone
Published
Updated
Nov 2, 2026, 3:39 PM
Reserved
Oct 6, 2026, 3:00 PM
Status
Awaiting Analysis
Published
Oct 23, 2026, 5:17 PM
Modified
Nov 2, 2026, 4:17 PM
Severity
Moderate
Public date
Oct 23, 2026, 4:15 PM