CVE-2026-106072
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**.
- Score
- CVSS 3.0 6.7 Medium
- Status
- Awaiting Analysis - support@hackerone.com
- Published
- 2026-10-23
- Last modified
- 2026-10-23
- Weaknesses
- CWE-295
Affected products
References
- https://nodejs.org/en/blog/vulnerability/october-2026-security-releases
