Bug 2560612

Summary: CVE-2026-106072 nodejs22: nodejs: Authentication bypass via non-canonical IPv4 hostname verification [fedora-43]
Product: [Fedora] Fedora Reporter: Srikanth Balasubramanian <sbalasub>
Component: nodejs22Assignee: Jan Staněk <jstanek>
Status: NEW --- QA Contact:
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Priority: medium    
Version: 43CC: aradchen, jstanek, tjuhasz
Target Milestone: ---Keywords: Security, SecurityTracking
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Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["822da0e2-24b2-4dac-928b-854bb7597f21"]}
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Blocks: 2560022    

Description Srikanth Balasubramanian 2026-10-26 11:44:52 UTC 
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.

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**.