GHSA-38rv-x7px-6hhq

ghsaUSosv

undici WebSocket client vulnerable to denial of service via cumulative fragment bypass

Advisory ansehen veröffentlicht 2026-06-18Lizenz: CC-BY-4.0

## Impact The undici WebSocket client enforces `maxPayloadSize` per-frame but does not enforce the cumulative size of fragmented uncompressed messages. A malicious WebSocket server can stream many small fragments that each pass per-frame validation but collectively exceed the configured limit, 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(...)`) that can be induced to connect to an attacker-controlled or compromised WebSocket endpoint. This is a regression specific to undici 8.1.0. The 6.25.0 line shipped the equivalent cumulative check from the start and is unaffected. The 7.x line never had the `maxPayloadSize` feature and is also unaffected. ## Patches Upgrade to undici >= 8.5.0. ## Workarounds No workaround is available. The fix must be applied through an upgrade.

01

beschreibt (1)

Zugehörige CVEs.

IDSchweregrad ausnutzbar
CVE-2026-9675US——
Impact: The undici WebSocket client enforces maxPayloadSize per-frame but does not enforce the cumulative size of fragmented uncompressed messages. A malicious WebSocket server can…
02

Referenzen

Externe Belege — Patches, Meldungen, Analysen.

scry

Advisories wie diese benennen die exponierten Produkte, die Angreifer auf Ihrer Angriffsfläche ins Visier nehmen. Sehen Sie mit einem kostenlosen Passiv-Scan, was exponiert ist.

Kostenloser Scan