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Fencer Intel
medium 6.8

CVE-2026-123877 json

Node.js is vulnerable to a certificate validation bypass in https.Agent via cross-policy TLS session reuse

published 16h ago modified 15h ago also EUVD-2026-123696

cvss
6.8
version 3.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
—
no EPSS score yet
public exploits
0
none known

Summary

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.

Patch / fix

  • nodejs node 22.23.5, 24.22.3, 26.13.1
  • nodejs Alpine 3.22, Alpine 3.21 22.23.5-r0
  • nodejs Alpine 3.24, Alpine 3.23 24.22.3-r0

alpine advisories ALPINE-CVE-2026-123877

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-123877 updated cvss 6.8

nodejs: nodejs: Certificate validation bypass via TLS session cache reuse

  • Red Hat Hardened Images nodejs25 25.9.0-1.7.hum1, nodejs20 20.20.2-1.3.hum1, nodejs24 24.22.2-0.2.hum1, nodejs26 26.13.0-0.1.1.hum1, nodejs22 22.23.4-2.3.2.3.1.hum1
    affected: workaround, no fix available, no fix planned “Will not fix”

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CVSS scores

assigned by version score vector
CNA 3.0 6.8 CVSS:3.0/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N

Affected products

  • nodejs node

Classification

Weakness
  • CWE-295 Improper Certificate Validation
Technology feeds

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.