{"timestamp":"2026-06-17T17:29:57.305732Z","id":"CVE-2026-12151","options":[{"exploitation":"none"},{"automatable":"yes"},{"technicalImpact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}

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.

AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CWE-400

CWE-770

https://cna.openjsf.org/security-advisories.html

https://github.com/nodejs/undici/security/advisories/GHSA-vxpw-j846-p89q

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