Is there a public exploit for CVE-2026-123864?

No public exploit for CVE-2026-123864 was found in Exploit-DB, Metasploit, Nuclei templates or public proof-of-concept repositories. That is an absence of evidence rather than proof that none exists.

How severe is CVE-2026-123864?

CVE-2026-123864 scores CVSS 8.1 (v3.0), rated high.

What does CVE-2026-123864 affect?

CVE-2026-123864 affects nodejs Node.

8.1 High

A re-entrancy flaw in Node.js HTTPS lets an unauthenticated client read memory belonging to other connections, including TLS private keys…

CVE-2026-123864

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 onbody callback, ClearOut() decrypts the next TLS record while the parser is still mid-body, re-entering llhttpexecute() 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.

Assessment

CVSS: 8.1 (v3.0)
Severity: High
Known exploited: Not listed in CISA KEV
Exploit availability: Nothing found in Exploit-DB, Metasploit, Nuclei or public PoC repositories
Published: 11 November 2026
Last updated: 11 November 2026
Affected: nodejs · Node
Assigner: openjs

CVSS vectorCVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:H

At the source

EUVD (ENISA)

References

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