Unintended Reentrant Invocation of Non-reentrant Code Via Nested Calls Affecting nodejs20 package, versions *


Severity

Recommended
0.0
high
0
10

Based on Red Hat Enterprise Linux security rating.

Threat Intelligence

EPSS
0.33% (28th percentile)

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  • Snyk IDSNYK-RHEL10-NODEJS20-22438616
  • published12 Nov 2026
  • disclosed11 Nov 2026

Introduced: 11 Nov 2026

NewCVE-2026-123864  (opens in a new tab)
CWE-1265  (opens in a new tab)

How to fix?

There is no fixed version for RHEL:10 nodejs20.

NVD Description

Note: Versions mentioned in the description apply only to the upstream nodejs20 package and not the nodejs20 package as distributed by RHEL. See How to fix? for RHEL:10 relevant fixed versions and status.

A re-entrancy flaw in Node.js HTTPS lets an unauthenticated client read memory belonging to other connections, including TLS private keys and other users' requests. TLSWrap::DoWrite() calls ClearOut() directly when asked to write zero bytes; if that write is issued from JavaScript running inside the HTTP parser's on_body callback, ClearOut() decrypts the next TLS record while the parser is still mid-body, re-entering llhttp_execute() and causing a use-after-free and an out-of-bounds heap read. The server then copies that freed or unrelated heap memory into the response for the request body. Triggering it requires a handler that calls res.flushHeaders() before the request body ends and later calls res.end() with a non-empty chunk, and reading the leaked memory requires any ordinary route that echoes or stores a request body. Cleartext node:http is not affected. This vulnerability affects Node.js 26.x, 24.x, and 22.x.

CVSS Base Scores

version 3.1