CVE-2026-12151

Fixed in a distro release EPSS <1%CVSS 7.5

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.

Published 2026-06-17 · CVE record · OSV

Products: undici, Red Hat Cryostat 4 on RHEL 9, Red Hat AMQ Broker 7.13.6, Red Hat AMQ Broker 7.14.1, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 10.0 Extended Update Support, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat Enterprise Linux 9.6 Extended Update Support, Red Hat Cluster Observability Operator 1.5.0, Red Hat Developer Hub 1.10, Red Hat Developer Hub 1.9, Red Hat Hardened Images, Red Hat OpenShift AI 2.25, Red Hat OpenShift AI 3.4, Red Hat OpenShift Container Platform 4.16, Red Hat OpenShift Container Platform 4.17, Red Hat Openshift Data Foundation 4.18, Red Hat Openshift Data Foundation 4.19, Red Hat Openshift Data Foundation 4.20, Red Hat OpenShift Dev Spaces 3.29, Red Hat OpenShift Dev Spaces 3.30, Red Hat Cryostat 4, Red Hat OpenShift Pipelines, Red Hat Build of Podman Desktop, Red Hat OpenShift AI (RHOAI), Red Hat OpenShift Container Platform 4, Red Hat Self-service automation portal 2

Fixed upstream

Distro releases