CVE-2026-12151
undici WebSocket client vulnerable to denial of service via fragment count bypass
At a glance
- Source
- NVD
- EPSS
- EPSS 0.79 % · percentile 56 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- openjs
- NVD status
- Modified
Description
Impact: The undici WebSocket client enforces maxPayloadSize on the cumulative byte count of fragments in a message but does not enforce a limit on the number of fragments. A malicious WebSocket server can stream many small or empty continuation frames that each pass per-frame and cumulative-size validation, collectively causing unbounded memory growth in the client process. The result is memory exhaustion and a denial of service. Affected applications are those using the undici WebSocket client (new WebSocket(...)) or the WebSocketStream API that can be induced to connect to an attacker-controlled or compromised WebSocket endpoint. All releases starting at undici 6.17.0 are affected. Patches: Upgrade to undici >= 6.26.0, >= 7.28.0, or >= 8.5.0. Workarounds: No workaround is available. The fix must be applied through an upgrade.
Weaknesses (CWE)
- CWE-400 — Uncontrolled Resource Consumption
- CWE-770 — Allocation of Resources Without Limits or Throttling
References
- https://github.com/nodejs/undici/security/advisories/GHSA-vxpw-j846-p89q
- https://cna.openjsf.org/security-advisories.html
- https://access.redhat.com/security/cve/CVE-2026-12151
- https://bugzilla.redhat.com/show_bug.cgi?id=2489980
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-12151.json
- https://access.redhat.com/errata/RHSA-2026:48151
- https://access.redhat.com/errata/RHSA-2026:39246
- https://access.redhat.com/errata/RHSA-2026:35842
- https://access.redhat.com/errata/RHSA-2026:35841
- https://access.redhat.com/errata/RHSA-2026:41947
- https://access.redhat.com/errata/RHSA-2026:39868
- https://access.redhat.com/errata/RHSA-2026:52399
- https://access.redhat.com/errata/RHSA-2026:35892
- https://access.redhat.com/errata/RHSA-2026:35891
- https://access.redhat.com/errata/RHSA-2026:34342
- https://access.redhat.com/errata/RHSA-2026:66545
- https://access.redhat.com/errata/RHSA-2026:66488
- https://access.redhat.com/errata/RHSA-2026:36754
- https://access.redhat.com/errata/RHSA-2026:41929
- https://access.redhat.com/errata/RHSA-2026:38236
- https://access.redhat.com/errata/RHSA-2026:38009
- https://access.redhat.com/errata/RHSA-2026:65126
- https://access.redhat.com/errata/RHSA-2026:60520
- https://access.redhat.com/errata/RHSA-2026:36621
- https://access.redhat.com/errata/RHSA-2026:47728
- https://access.redhat.com/errata/RHSA-2026:48124
- https://access.redhat.com/errata/RHSA-2026:36820
- https://access.redhat.com/errata/RHSA-2026:62260
- https://access.redhat.com/errata/RHSA-2026:56431
- https://access.redhat.com/errata/RHSA-2026:56366
- https://access.redhat.com/errata/RHSA-2026:57013
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 | redhat-SADP |
| 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) |
| 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 · 0b0ca135-0b70-47e7-9f44-1890c2a1c46c (Secondary) |
Advisories
- GHSA-vxpw-j846-p89q — undici WebSocket client vulnerable to denial of service via fragment count bypass
European references
- ENISA EUVD · EUVD-2026-37747
- GCVE · GCVE-0-2026-12151
CERT-FR advisories
- CERTFR-2026-AVI-1094 — Multiples vulnérabilités dans les produits IBM · cert.ssi.gouv.fr
Affected configurations (NVD CPE)
cpe:2.3:a:nodejs:undici:*:*:*:*:*:node.js:*:*≥ 6.17.0 < 6.27.0cpe:2.3:a:nodejs:undici:*:*:*:*:*:node.js:*:*≥ 7.0.0 < 7.28.0cpe:2.3:a:nodejs:undici:*:*:*:*:*:node.js:*:*≥ 8.0.0 < 8.5.0
Affected products
| Product | Versions |
|---|---|
| undici · undici | affected 0 < 6.26.0 ; unaffected 6.26.0 ; affected 7.0.0 < 7.28.0 ; unaffected 7.28.0 ; affected 8.0.0 < 8.5.0 ; unaffected 8.5.0 |
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 |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| 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 |