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.

The nodejs module Undici detected on the host is version 8.1.x prior to 8.5.0. It is, therefore, affected by a denial of service vulnerability:

  - 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. (CVE-2026-9675)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - 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.
    (CVE-2026-9675)

Note that Nessus relies on the presence of the package as reported by the vendor.

There are packages installed that are affected by a vulnerability referenced in the following CVE:

  - 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.
    (CVE-2026-9675)

ID	Name	Product	Family	Severity
322410	Node.js Module Undici 8.1.x < 8.5.0 DoS (CVE-2026-9675)	Nessus	Misc.	high
321575	Linux Distros Unpatched Vulnerability : CVE-2026-9675	Nessus	Misc.	high
443557	SCA: security update for undici (GHSA-38rv-x7px-6hhq)	Tenable Cloud Security	SCA Checks	high
443557	SCA: security update for undici (GHSA-38rv-x7px-6hhq)	Tenable Self-Hosted Container Security	SCA Checks	high

Detections

Analytics

CVE-2026-9675

high

Tenable Plugins

high

high

high

high