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 li
What fixes it
No source in this snapshot names a fixed version. The vendor advisories under References are the place to check.
Timeline
- 23 Oct 2026, 16:15 UTCPublishedCVE List
- 23 Oct 2026, 23:47 UTCExploit code publicGitHub proof-of-concept repositories
Reports 1
1 outlet mention it. Reports are not confirmation; each links to its source.
Description
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.
Text from CVE List
Affected versions 3
- nodeaffected: 22.23.3 through 22.23.3CVE List
- nodeaffected: 24.22.0 through 24.22.0CVE List
- nodeaffected: 26.12.0 through 26.12.0CVE List