undici WebSocket client vulnerable to Denial of Service via failed HTTP/2 handshake (undici undici)
At a glance
- Source
- NVD
- EPSS
- EPSS 0.28 % · percentile 20 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- openjs
- NVD status
- Analyzed
Description
undici is an HTTP client library for Node.js. In versions 8.11.0 and 8.11.1, its experimental WebSocket client, which is enabled by default when HTTP/2 is allowed, mishandles a failed WebSocket handshake over HTTP/2: the request is already marked completed, so the abort becomes a no-op and the underlying HTTP/2 stream is left open with no error listener. When a malicious server then destroys the connection, the orphaned stream emits an unhandled error and the Node.js process exits. A remote, unauthenticated server can therefore crash any client that opens a WebSocket to it over HTTP/2, resulting in a denial of service. The issue is fixed in undici 8.11.2, and users should upgrade to 8.11.2 or later. As a workaround, set allowH2 to false to disable HTTP/2 for WebSocket connections, or avoid opening WebSocket connections to untrusted servers.
Weaknesses (CWE)
References
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | HIGH 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | openjs |
| CVSS 3.1 | HIGH 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | NVD · ce714d77-add3-4f53-aff5-83d477b104bb (Secondary) |
Advisories
- GHSA-qq8j-7v2v-3rwp — undici WebSocket client vulnerable to Denial of Service via failed HTTP/2 handshake
European references
- ENISA EUVD · EUVD-2026-101959
- GCVE · GCVE-0-2026-109855
Affected configurations (NVD CPE)
cpe:2.3:a:nodejs:undici:*:*:*:*:*:node.js:*:*≥ 8.11.0 < 8.11.2
Affected products
| Product | Versions |
|---|---|
| undici · undici | affected 8.11.0 < 8.11.2 ; unaffected 8.11.2 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |