7.5
HIGH
CVSS 3.1
CVE-2026-2229
undici is vulnerable to Unhandled Exception in undici WebSocket Client Due to Invalid server_max_window_bits Validation
Overview
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
Details
INFO
Published Date :
March 12, 2026, 9:16 p.m.
Last Modified :
July 2, 2026, 12:17 p.m.
Remotely Exploit :
Yes !
Source :
ce714d77-add3-4f53-aff5-83d477b104bb
Scoring
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework
for assessing the severity of vulnerabilities in software and systems.
We collect and displays CVSS scores from various sources for each CVE.
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | HIGH | ce714d77-add3-4f53-aff5-83d477b104bb | ||||
| CVSS 3.1 | HIGH | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c |
Solution
Update the undici WebSocket client to a version that validates the server_max_window_bits parameter.
- Update the undici WebSocket client to the latest version.
- Ensure server_max_window_bits is validated.
- Wrap createInflateRaw calls in a try-catch block.
Public PoC/Exploit Available at Github
CVE-2026-2229 has a 1 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
References
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-2229.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-2229 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-2229
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Aisle CVEs
Updated: 3 weeks ago
0 stars
0 fork
0 watcher
Born at : June 15, 2026, 10:03 a.m.
This repo has been linked 217 different CVEs too.
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-2229 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-2229 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
Jul. 02, 2026
Action Type Old Value New Value Added Reference https://access.redhat.com/errata/RHSA-2026:34342 Changed Affected [{'cpes': ['cpe:/a:redhat:cryostat:4::el9'], 'vendor': 'Red Hat', 'product': 'Cryostat 4 on RHEL 9', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:enterprise_linux_eus:10.0'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream EUS (v. 10.0)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:enterprise_linux:10.1'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream (v. 10)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:enterprise_linux:8::appstream'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream (v. 8)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_eus:9.6::appstream'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream EUS (v.9.6)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:enterprise_linux:9::appstream'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream (v. 9)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhdh:1.8::el9'], 'vendor': 'Red Hat', 'product': 'Red Hat Developer Hub 1.8', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhdh:1.9::el9'], 'vendor': 'Red Hat', 'product': 'Red Hat Developer Hub 1.9', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:openshift_ai:2.16::el8'], 'vendor': 'Red Hat', 'product': 'Red Hat OpenShift AI 2.16', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:openshift_devspaces:3.28::el9'], 'vendor': 'Red Hat', 'product': 'Red Hat OpenShift Dev Spaces 3.28', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:openshift_pipelines:1.20::el9'], 'vendor': 'Red Hat', 'product': 'Red Hat OpenShift Pipelines 1.2', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:openshift_lightspeed'], 'vendor': 'Red Hat', 'product': 'OpenShift Lightspeed', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:openshift_pipelines:1'], 'vendor': 'Red Hat', 'product': 'OpenShift Pipelines', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhdh:1'], 'vendor': 'Red Hat', 'product': 'Red Hat Developer Hub', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:openshift_ai'], 'vendor': 'Red Hat', 'product': 'Red Hat OpenShift AI (RHOAI)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:ansible_portal:2'], 'vendor': 'Red Hat', 'product': 'Self-service automation portal 2', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:jboss_enterprise_application_platform:8'], 'vendor': 'Red Hat', 'product': 'Red Hat JBoss Enterprise Application Platform 8', 'defaultStatus': 'unaffected'}, {'cpes': ['cpe:/a:redhat:jbosseapxp'], 'vendor': 'Red Hat', 'product': 'Red Hat JBoss Enterprise Application Platform Expansion Pack', 'defaultStatus': 'unaffected'}, {'cpes': ['cpe:/a:redhat:openshift_devspaces:3'], 'vendor': 'Red Hat', 'product': 'Red Hat OpenShift Dev Spaces', 'defaultStatus': 'unaffected'}] [{'cpes': ['cpe:/a:redhat:cryostat:4::el9'], 'vendor': 'Red Hat', 'product': 'Cryostat 4 on RHEL 9', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:enterprise_linux_eus:10.0'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream EUS (v. 10.0)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:enterprise_linux:10.1'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream (v. 10)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:enterprise_linux:8::appstream'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream (v. 8)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_eus:9.6::appstream'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream EUS (v.9.6)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:enterprise_linux:9::appstream'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream (v. 9)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:cluster_observability_operator:1.5::el9'], 'vendor': 'Red Hat', 'product': 'Cluster Observability Operator 1.5.0', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhdh:1.8::el9'], 'vendor': 'Red Hat', 'product': 'Red Hat Developer Hub 1.8', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhdh:1.9::el9'], 'vendor': 'Red Hat', 'product': 'Red Hat Developer Hub 1.9', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:openshift_ai:2.16::el8'], 'vendor': 'Red Hat', 'product': 'Red Hat OpenShift AI 2.16', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:openshift_devspaces:3.28::el9'], 'vendor': 'Red Hat', 'product': 'Red Hat OpenShift Dev Spaces 3.28', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:openshift_pipelines:1.20::el9'], 'vendor': 'Red Hat', 'product': 'Red Hat OpenShift Pipelines 1.2', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:openshift_lightspeed'], 'vendor': 'Red Hat', 'product': 'OpenShift Lightspeed', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:openshift_pipelines:1'], 'vendor': 'Red Hat', 'product': 'OpenShift Pipelines', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhdh:1'], 'vendor': 'Red Hat', 'product': 'Red Hat Developer Hub', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:openshift_ai'], 'vendor': 'Red Hat', 'product': 'Red Hat OpenShift AI (RHOAI)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:ansible_portal:2'], 'vendor': 'Red Hat', 'product': 'Self-service automation portal 2', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:jboss_enterprise_application_platform:8'], 'vendor': 'Red Hat', 'product': 'Red Hat JBoss Enterprise Application Platform 8', 'defaultStatus': 'unaffected'}, {'cpes': ['cpe:/a:redhat:jbosseapxp'], 'vendor': 'Red Hat', 'product': 'Red Hat JBoss Enterprise Application Platform Expansion Pack', 'defaultStatus': 'unaffected'}, {'cpes': ['cpe:/a:redhat:openshift_devspaces:3'], 'vendor': 'Red Hat', 'product': 'Red Hat OpenShift Dev Spaces', 'defaultStatus': 'unaffected'}] -
CVE Modified by 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
Jun. 30, 2026
Action Type Old Value New Value Added Affected [{'cpes': ['cpe:/a:redhat:cryostat:4::el9'], 'vendor': 'Red Hat', 'product': 'Cryostat 4 on RHEL 9', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:enterprise_linux_eus:10.0'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream EUS (v. 10.0)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/o:redhat:enterprise_linux:10.1'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream (v. 10)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:enterprise_linux:8::appstream'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream (v. 8)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhel_eus:9.6::appstream'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream EUS (v.9.6)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:enterprise_linux:9::appstream'], 'vendor': 'Red Hat', 'product': 'Red Hat Enterprise Linux AppStream (v. 9)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhdh:1.8::el9'], 'vendor': 'Red Hat', 'product': 'Red Hat Developer Hub 1.8', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhdh:1.9::el9'], 'vendor': 'Red Hat', 'product': 'Red Hat Developer Hub 1.9', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:openshift_ai:2.16::el8'], 'vendor': 'Red Hat', 'product': 'Red Hat OpenShift AI 2.16', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:openshift_devspaces:3.28::el9'], 'vendor': 'Red Hat', 'product': 'Red Hat OpenShift Dev Spaces 3.28', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:openshift_pipelines:1.20::el9'], 'vendor': 'Red Hat', 'product': 'Red Hat OpenShift Pipelines 1.2', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:openshift_lightspeed'], 'vendor': 'Red Hat', 'product': 'OpenShift Lightspeed', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:openshift_pipelines:1'], 'vendor': 'Red Hat', 'product': 'OpenShift Pipelines', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:rhdh:1'], 'vendor': 'Red Hat', 'product': 'Red Hat Developer Hub', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:openshift_ai'], 'vendor': 'Red Hat', 'product': 'Red Hat OpenShift AI (RHOAI)', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:ansible_portal:2'], 'vendor': 'Red Hat', 'product': 'Self-service automation portal 2', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:jboss_enterprise_application_platform:8'], 'vendor': 'Red Hat', 'product': 'Red Hat JBoss Enterprise Application Platform 8', 'defaultStatus': 'unaffected'}, {'cpes': ['cpe:/a:redhat:jbosseapxp'], 'vendor': 'Red Hat', 'product': 'Red Hat JBoss Enterprise Application Platform Expansion Pack', 'defaultStatus': 'unaffected'}, {'cpes': ['cpe:/a:redhat:openshift_devspaces:3'], 'vendor': 'Red Hat', 'product': 'Red Hat OpenShift Dev Spaces', 'defaultStatus': 'unaffected'}] Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Added CWE CWE-248 Added Reference https://access.redhat.com/errata/RHSA-2026:13826 Added Reference https://access.redhat.com/errata/RHSA-2026:17789 Added Reference https://access.redhat.com/errata/RHSA-2026:21772 Added Reference https://access.redhat.com/errata/RHSA-2026:21931 Added Reference https://access.redhat.com/errata/RHSA-2026:5807 Added Reference https://access.redhat.com/errata/RHSA-2026:7080 Added Reference https://access.redhat.com/errata/RHSA-2026:7123 Added Reference https://access.redhat.com/errata/RHSA-2026:7302 Added Reference https://access.redhat.com/errata/RHSA-2026:7310 Added Reference https://access.redhat.com/errata/RHSA-2026:7350 Added Reference https://access.redhat.com/errata/RHSA-2026:7670 Added Reference https://access.redhat.com/errata/RHSA-2026:7675 Added Reference https://access.redhat.com/errata/RHSA-2026:7983 Added Reference https://access.redhat.com/errata/RHSA-2026:9742 Added Reference https://access.redhat.com/security/cve/CVE-2026-2229 Added Reference https://bugzilla.redhat.com/show_bug.cgi?id=2447143 Added Reference https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-2229.json -
CVE Modified by ce714d77-add3-4f53-aff5-83d477b104bb
Jun. 17, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://github.com/nodejs/undici/', 'vendor': 'undici', 'product': 'undici', 'versions': [{'status': 'affected', 'version': '< 6.24.0; 7.0.0 < 7.24.0'}, {'status': 'unaffected', 'version': '6.24.0: 7.24.0'}], 'packageName': 'undici', 'collectionURL': 'https://github.com/nodejs/undici/', 'defaultStatus': 'unaffected'}] -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jun. 17, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-2229', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'yes'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-03-13T13:06:30.575811Z'} -
Initial Analysis by [email protected]
Mar. 20, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:nodejs:undici:*:*:*:*:*:node.js:*:* versions up to (excluding) 6.24.0 *cpe:2.3:a:nodejs:undici:*:*:*:*:*:node.js:*:* versions from (including) 7.0.0 up to (excluding) 7.24.0 Added Reference Type openjs: https://cna.openjsf.org/security-advisories.html Types: Vendor Advisory Added Reference Type openjs: https://datatracker.ietf.org/doc/html/rfc7692 Types: Technical Description Added Reference Type openjs: https://github.com/nodejs/undici/security/advisories/GHSA-v9p9-hfj2-hcw8 Types: Vendor Advisory Added Reference Type openjs: https://hackerone.com/reports/3487486 Types: Permissions Required Added Reference Type openjs: https://nodejs.org/api/zlib.html#class-zlibinflateraw Types: Technical Description -
New CVE Received by ce714d77-add3-4f53-aff5-83d477b104bb
Mar. 12, 2026
Action Type Old Value New Value Added 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 Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Added CWE CWE-248 Added CWE CWE-1284 Added Reference https://cna.openjsf.org/security-advisories.html Added Reference https://datatracker.ietf.org/doc/html/rfc7692 Added Reference https://github.com/nodejs/undici/security/advisories/GHSA-v9p9-hfj2-hcw8 Added Reference https://hackerone.com/reports/3487486 Added Reference https://nodejs.org/api/zlib.html#class-zlibinflateraw
EPSS is a daily estimate of the probability of exploitation activity
being observed over the next 30 days. Following chart shows the EPSS
score history of the vulnerability.