A flaw in Node.js TLS hostname verification can cause a server certificate to be validated against a different IP address than the one the client connected to, when the host is a non-canonical IPv4 literal with a leading zero, such as `0127.0.0.1`. `tls.checkServerIdentity()` normalizes the host following the WHATWG URL rules, which read a leading-zero octet as octal (`0127.0.0.1` becomes `87.0.0.1`), while the connection is made through the operating system resolver, which on some platforms such as macOS reads it as decimal (`127.0.0.1`). A server at the connected address can then be authenticated with a certificate issued for another IP address. This vulnerability affects Node.js **26.x**, **24.x**, and **22.x**.
Fix
Microsoft's update · Important
- Release Notes — azl3 nodejs 24.21.0-1 on Azure Linux 3.0 · build 24.22.1-0
From the 2026-Oct release note of Microsoft's Security Update Guide, revised 2026-10-28.
Public exploits 2
- CompleTetech-Security/node-cve-2026-106069-check PoC on GitHub
- completetech-security/node-cve-2026-106069-check PoC on GitHub
Each line links to the index that lists it, never to exploit code. Exploit-DB's "verified" and a Metasploit rank of good or better count as verified; a PoC-in-GitHub entry is a repository's claim.
Vendor advisories in the News 1
- Node2Shell CVEs Fortinet PSIRT Advisories · 2026-10-26
Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.
Change history 4
- StatusAwaiting Analysis → PublishedNVD modified 2026-10-23 16:15
- StatusPublished → Awaiting AnalysisNVD modified 2026-10-23 19:42
- StatusReceived → PublishedNVD modified 2026-10-23 16:15
- First seenCVSS 7.4NVD modified 2026-10-23 17:17
Affected (CPE criteria) 0
NVD has not attached CPE configurations yet.