CVE-2026-12151: undici WebSocket client vulnerable to denial of service via fragment count bypass
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.
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H · CWE-400, CWE-770
Tracked companies
Mapped from the CVE’s affected-product data, NVD CPE matches, vendor advisories or package feeds. A mapping means the vendor’s software is named, not that its hosted service was exposed.
Status incidents that name it
No tracked status incident names this CVE.
Affected vendors and products
Red Hat: Cluster Observability Operator 1.5.0Red Hat: Cryostat 4Red Hat: Cryostat 4 on RHEL 9Red Hat: OpenShift PipelinesRed Hat: Red Hat AMQ Broker 7.13.6Red Hat: Red Hat AMQ Broker 7.14.1Red Hat: Red Hat Build of Podman DesktopRed Hat: Red Hat Enterprise Linux 10Red Hat: Red Hat Enterprise Linux 10.0 Extended Update SupportRed Hat: Red Hat Enterprise Linux 8Red Hat: Red Hat Enterprise Linux 9Red Hat: Red Hat Enterprise Linux 9.6 Extended Update SupportRed Hat: Red Hat Hardened ImagesRed Hat: Red Hat OpenShift AI 2.25Red Hat: Red Hat OpenShift AI 3.4Red Hat: Red Hat OpenShift AI (RHOAI)Red Hat: Red Hat OpenShift Container Platform 4Red Hat: Red Hat OpenShift Container Platform 4.16Red Hat: Red Hat OpenShift Container Platform 4.17Red Hat: Red Hat Openshift Data Foundation 4.18Red Hat: Self-service automation portal 2undici: undici
References
- CVE record on cve.org (opens in new tab)
- NVD entry (opens in new tab)
- cna.openjsf.org/security-advisories.html (opens in new tab)
- github.com/nodejs/undici/security/advisories/GHSA-vxpw-j846-p89q (opens in new tab)
- CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (opens in new tab)
- This product uses data from the NVD API but is not endorsed or certified by the NVD. (opens in new tab)
- Known Exploited Vulnerabilities catalog from CISA. (opens in new tab)
- EPSS scores from FIRST (Exploit Prediction Scoring System). (opens in new tab)