ChangeIntel IT change radar
Public mode

No access to your tenant or devices. Every item links to its source. What this means

Sources need attention Customize Public modeDiscuss ChangeIntel on Discord
CVE-2026-2229

undici · Vulnerability

CVSS 3.1 7.5 HIGHCheck source for fixed versionsKEV status unknown
Original advisory

Historical advisory recorded 23 Oct 2026 15:48:27 UTC. Read the latest advisory.

cve-program · CVE-2026-2229

Published

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

Read the publisher's advisory

Affected versions, risk and source history

cve-program · CVE-2026-2229

Published

undici

https://github.com/nodejs/undici/

Publisher's version information

Shown as published. These rules are not interpreted as NuGet package version ranges.

{
                    "vendor": "undici",
                    "product": "undici",
                    "collectionURL": "https://github.com/nodejs/undici/",
                    "packageName": "undici",
                    "repo": "https://github.com/nodejs/undici/",
                    "versions": [
                        {
                            "status": "affected",
                            "version": "< 6.24.0; 7.0.0 < 7.24.0"
                        },
                        {
                            "status": "unaffected",
                            "version": "6.24.0: 7.24.0"
                        }
                    ],
                    "defaultStatus": "unaffected"
                }

Original source record · Cite this exact observation · Complete original publisher JSON

ChangeIntel

An IT change radar: releases, security, known issues, retirements, documentation changes, and service status from public sources. Every item links to supporting evidence; dates and statuses can change after they are read.

Sources read 15 Nov 23:13 UTC · 274 of 275 readable · 250 fully read · 18 waiting for GitHub's hourly limit · documentation 461/469 current

No accounts or analytics; your preferences stay in your browser. Information, not advice. ChangeIntel is an independent tool and is not affiliated with or endorsed by Microsoft, Apple, Google, Broadcom (VMware), Jamf, Oracle, Mozilla, or any other vendor it covers. Product names are trademarks of their owners.