# CVE-2026-123877 — nodejs node

> As of 2026-11-12, CVE-2026-123877 is a MEDIUM-severity vulnerability in nodejs node, CVSS v3.1 6.8. Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2026-123877, most recently “Node.js November 2026 Security Releases Patch 16 Vulnerabilities (HTTP/2 crashes, HTTPS heap/TLS key leak CVE-2026-123864, TLS client-certificate auth bypass)”.

**Last updated:** 2026-11-12

## What is CVE-2026-123877?

A certificate validation bypass in Node.js https.Agent lets a cached TLS session authenticated under one CA policy be reused by a later request with a stricter policy. https.Agent.prototype.getName() assigns the same Agent and session-cache key to a request that omits ca and one that explicitly supplies ca: [], because an omitted value appends nothing to the key while an empty array stringifies to an empty string. The two policies differ: omitting ca uses the default trust store, while supplying ca replaces it. Since they share a key, a TLS session authenticated under the broader default policy is handed to a new connection made under the later ca: [] policy, and TLS 1.3 session resumption carries the earlier authentication forward, so the second request reports authorized === true and transmits confidential data to a server its own CA policy would reject on a fresh connection. This vulnerability affects Node.js 26.x, 24.x, and 22.x.

The record classifies CVE-2026-123877 under weakness class [CWE-295](https://intel.threadlinqs.com/cwe/CWE-295). Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs low-privilege credentials, needs no user interaction, and has high impact on confidentiality, integrity. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 1 day ago.

## Severity and exploitation probability

- **CVSS v3.1 base score:** 6.8 — MEDIUM (`CVSS:3.0/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N`)
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 3.4/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-11-11

## Is CVE-2026-123877 being exploited?

It currently carries a trending score of 5 in the Threadlinqs vulnerability feed.

## Affected products and versions

- [nodejs](https://intel.threadlinqs.com/vendors/nodejs): node

## How to fix CVE-2026-123877

Vendor advisory: [https://nodejs.org/en/blog/vulnerability/november-2026-security-releases](https://nodejs.org/en/blog/vulnerability/november-2026-security-releases). Apply the vendor fix referenced above to every affected product listed in this record, then confirm the running version against the vendor advisory.

## Threat activity tracking CVE-2026-123877

1 tracked threat in the Threadlinqs corpus references CVE-2026-123877, either in the campaign’s CVE list or as an indicator on the campaign record.

- [Node.js November 2026 Security Releases Patch 16 Vulnerabilities (HTTP/2 crashes, HTTPS heap/TLS key leak CVE-2026-123864, TLS client-certificate auth bypass)](https://intel.threadlinqs.com/threat/TL-2026-5828) — HIGH · 2026-11-12

## Sources

Enriched from CVE.org, NVD. This product uses the NVD API but is not endorsed or certified by the NVD.

**Vendor advisory and patch**

- [nodejs.org — vendor advisory](https://nodejs.org/en/blog/vulnerability/november-2026-security-releases)

**Other references**

- [cna.openjsf.org](https://cna.openjsf.org/security-advisories.html)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-123877
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