A flaw in Node.js TLS hostname verification allows a certificate without a matching IP address SAN to authenticate a connection to an IPv4 address when the host is written with non-ASCII characters, such as fullwidth digits (`１２７.0.0.1`).
`tls.checkServerIdentity()` did not recognize such hosts as IP addresses, even though they normalize and resolve to a regular IPv4 address, and matched them against the certificate DNS names and Common Name instead. A certificate containing `DNS:127.0.0.1` or `DNS:*.0.0.1` could therefore be accepted for an IP endpoint it was not issued for. This is a regression introduced after the fix for CVE-2026-48618.
This vulnerability affects Node.js **26.x** and **24.x**.
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Nodejs | — | Upgrade Node.js to version 24.22.1Upgrade Node.js to version 26.12.1Upgrade to the latest version of Node.js | Oct 26, 2026 | Oct 23, 2026 |
| Redhat_linux | — | No solution exists | Oct 26, 2026 | Oct 21, 2026 |
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