CVE-2026-103936

libp2p: Single pre-auth STUN packet terminates `@libp2p/webrtc` WebRTC-direct Node.js listeners

HIGH
7.5
CVSS Score
Published: October 15, 2026 at 05:28 PM UTC
Updated: October 16, 2026 at 08:04 PM UTC
2 products affected across 1 vendorwebrtcLIBP2P

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Severity
HIGH7.5
Exploit prediction
EPSS 0.5%
SSVC
No known exploit

Description

libp2p is a JavaScript implementation of the libp2p networking stack. Prior to 6.0.28, the @libp2p/webrtc webRTCDirect() Node.js listener processes unauthenticated STUN Binding Requests before PeerId authentication, Noise, muxing, protocol negotiation, connection creation, or connection-manager admission. The listener in packages/transport-webrtc/src/private-to-public/utils/stun-listener.ts forwards the packet-controlled request.ufrag into DirectRTCPeerConnection.setLocalDescription, where the value is reused as an ICE password without validating its required length and character set. A short credential causes node-datachannel or libdatachannel to raise an uncaught native invalid_argument and abort the process with SIGABRT, allowing a single remote UDP packet to deny service. The confirmed impact is process termination only, with no demonstrated memory corruption, code execution, browser impact, confidentiality impact, integrity impact, or connection-limit bypass. This issue is fixed in version 6.0.28.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 6.0.28
v < 3.3.7

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.5HIGHGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-248CWE-755

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