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CVE-2026-2229 Detail

Description

ImpactThe undici WebSocket client is vulnerable to a denial-of-service attack due to improper validation of the server_max_window_bits parameter in the permessage-deflate extension. When a WebSocket client connects to a server, it automatically advertises support for permessage-deflate compression. A malicious server can respond with an out-of-range server_max_window_bits value (outside zlib's valid range of 8-15). When the server subsequently sends a compressed frame, the client attempts to create a zlib InflateRaw instance with the invalid windowBits value, causing a synchronous RangeError exception that is not caught, resulting in immediate process termination. The vulnerability exists because: * The isValidClientWindowBits() function only validates that the value contains ASCII digits, not that it falls within the valid range 8-15 * The createInflateRaw() call is not wrapped in a try-catch block * The resulting exception propagates up through the call stack and crashes the Node.js process


Metrics

NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

References to Advisories, Solutions, and Tools

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URL Source(s) Tag(s)
https://cna.openjsf.org/security-advisories.html openjs
https://datatracker.ietf.org/doc/html/rfc7692 openjs
https://github.com/nodejs/undici/security/advisories/GHSA-v9p9-hfj2-hcw8 openjs
https://hackerone.com/reports/3487486 openjs
https://nodejs.org/api/zlib.html#class-zlibinflateraw openjs

Weakness Enumeration

CWE-ID CWE Name Source
CWE-248 Uncaught Exception openjs  
CWE-1284 Improper Validation of Specified Quantity in Input openjs  

Change History

1 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2026-2229
NVD Published Date:
03/12/2026
NVD Last Modified:
03/13/2026
Source:
openjs