CVE-2026-106069
HIGH
MEDIUM
Priority: 0.02
BB Relevance:
65/100
Published: 2026-10-23
Modified: 2026-10-23
First seen: 2026-10-29
Status: active
Attack Surface
Network
No Auth
No Interaction
Conf. Impact
Integ. Impact
CVSS Vector Breakdown
AV:
Network
AC:
High
PR:
None
UI:
None
S:
Unchanged
C:
High
I:
High
A:
None
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**.