{"cve":"CVE-2026-55663","nvd":{"published":"2026-08-25T19:16:51.060","modified":"2026-09-09T21:07:31.353","status":"Deferred","description":"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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L","score":5.6},"cwes":["CWE-345"],"references":["https://github.com/versatica/mediasoup/commit/9c1a90a8f9206b965e727d134846fb42df4980a7","https://github.com/versatica/mediasoup/pull/1829","https://github.com/versatica/mediasoup/releases/tag/3.20.6","https://github.com/versatica/mediasoup/security/advisories/GHSA-p7x2-g5cq-fhmq","https://github.com/versatica/mediasoup/security/advisories/GHSA-p7x2-g5cq-fhmq"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:50:17.453294893+00:00"},"epss":{"cve":"CVE-2026-55663","score":0.00188,"percentile":0.08404,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-p7x2-g5cq-fhmq","url":"https://osv.dev/vulnerability/GHSA-p7x2-g5cq-fhmq","summary":"mediasoup: SCTP state cookie lacks cryptographic authentication, enabling unauthorized association establishment (RFC 9260 violation)","modified":"2026-08-26T01:18:34.692749539Z","packages":[{"ecosystem":"npm","name":"mediasoup","purl":"pkg:npm/mediasoup","ranges":[">=3.20.0 <3.20.6"],"fixed":["3.20.6"]},{"ecosystem":"crates.io","name":"mediasoup","purl":"pkg:cargo/mediasoup","ranges":[">=0.22.0 <0.22.5"],"fixed":["0.22.5"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}