Is CVE-2026-123867 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-123867 being exploited in the wild.

How severe is CVE-2026-123867?

Medium severity, with a CVSS score of 4.2, published 11 November 2026.

Which products and versions are affected?

OpenJS Foundation Node.js 22.x, 24.x, 26.x.

Is there a fix for CVE-2026-123867?

No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

How is CVE-2026-123867 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-123867?

Check whether you run OpenJS Foundation Node.js at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-123867: Node.js mutual-TLS authorization bypass via CA-only SNI context

CVE-2026-123867 · Severity: medium · CVSS 4.2 · Published 2026-11-11

Node.js is a runtime environment for building server applications. This vulnerability allows a client that holds a certificate trusted by the default certificate authority to bypass mutual TLS authorization and access hostnames protected by a different certificate authority. An attacker with a valid default certificate could read responses intended only for clients with specific per-host certificates.

Technologies: OpenJS Foundation Node.js. Vendors: OpenJS Foundation.

Quick answers

Is CVE-2026-123867 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-123867 being exploited in the wild.
How severe is CVE-2026-123867?: Medium severity, with a CVSS score of 4.2, published 11 November 2026.
Which products and versions are affected?: OpenJS Foundation Node.js 22.x, 24.x, 26.x.
Is there a fix for CVE-2026-123867?: No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-123867 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-123867?: Check whether you run OpenJS Foundation Node.js at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

A per-host mutual-TLS authorization bypass occurs in Node.js when a TLS server configures a CA-only SNI context via server.addContext(host, { ca: protectedCA }) without a server certificate. The CertCbDone function in src/crypto/crypto_tls.cc installs the SNI context's CA only when setSniContext succeeds, but setSniContext returns false for contexts lacking a server certificate, causing the handshake to silently fall back to the default CA. A client holding a certificate trusted by the default CA but not the protected CA can complete mTLS to the protected hostname and read its response, bypassing requestCert and rejectUnauthorized protections.

Affected products

OpenJS Foundation Node.js 22.x, 24.x, 26.x

Timeline

2026-11-11: disclosed
2026-11-11: advisory

References

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