CVE-2026-55663

The record

mediasoup is a WebRTC video conferencing system. From version 3.20.0 until 3.20.6 for the npm package and from 0.22.0 until 0.22.5 for the Rust crate, mediasoup's built-in SCTP stack authenticates state cookies using only the hardcoded msworker and 0xAD81 magic values instead of a per-instance secret and HMAC, contrary to RFC 9260 Section 5.1.3. The cookie structure and validation in worker/include/RTC/SCTP/association/StateCookie.hpp and worker/src/RTC/SCTP/association/StateCookie.cpp allow an on-path attacker targeting PlainTransport or PipeTransport with SCTP enabled and without DTLS protection to forge a COOKIE-ECHO whose packet verification tag matches the attacker-controlled localVerificationTag. The forged cookie passes StateCookie::IsMediasoupStateCookie() and Association::HandleReceivedCookieEchoChunk(), establishes an unauthorized SCTP association, and permits DataChannel message injection as a trusted peer. WebRtcTransport is not affected because its SCTP runs inside DTLS. This issue is fixed in npm version 3.20.6 and Rust crate version 0.22.5.

Affected packages

Related vulnerabilities

• CVE-2026-102682 Pipecat is an open-source Python framework for building real-time voice and multimodal… CWE-345
• CVE-2026-104850 MCP TypeScript SDK is the official TypeScript SDK for Model Context Protocol servers and… CWE-345
• CVE-2026-102275 PyJWT is a Python implementation of JSON Web Token standards. CWE-345
• CVE-2026-102267 PyJWT is a Python implementation of JSON Web Token standards. CWE-345
• CVE-2026-19941 An inapplicable NSEC record may be accepted by a `named` resolver as proof that no… CWE-345
• CVE-2026-77955 In NLnet Labs Unbound 1.13.2 up to and including 1.26.1, a vulnerability in ZONEMD… CWE-345
• CVE-2026-89251 AVideo through commit c3edcc274c389816d434acadac07ee78eaf330c1 fails to validate ad… CWE-345
• CVE-2026-86809 The Persian Elementor WordPress plugin from 2.7.10 before 2.8.2 does not verify that the… CWE-345