FKIE_CVE-2026-55663

Vulnerability from fkie_nvd - Published: 2026-08-25 19:16 - Updated: 2026-09-09 21:07
Severity
5.6 (Medium) - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L
Summary
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.
References
security-advisories@github.comhttps://github.com/versatica/mediasoup/commit/9c1a90a8f9206b965e727d134846fb42df4980a7
security-advisories@github.comhttps://github.com/versatica/mediasoup/pull/1829
security-advisories@github.comhttps://github.com/versatica/mediasoup/releases/tag/3.20.6
security-advisories@github.comhttps://github.com/versatica/mediasoup/security/advisories/GHSA-p7x2-g5cq-fhmq
134c704f-9b21-4f2e-91b3-4a467353bcc0https://github.com/versatica/mediasoup/security/advisories/GHSA-p7x2-g5cq-fhmq
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "mediasoup",
          "vendor": "versatica",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 3.20.0, \u003c 3.20.6"
            },
            {
              "status": "affected",
              "version": "\u003e= 0.22.0, \u003c 0.22.5"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "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\u0027s 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."
    }
  ],
  "id": "CVE-2026-55663",
  "lastModified": "2026-09-09T21:07:31.353",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "HIGH",
          "attackVector": "NETWORK",
          "availabilityImpact": "LOW",
          "baseScore": 5.6,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "LOW",
          "integrityImpact": "LOW",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L",
          "version": "3.1"
        },
        "exploitabilityScore": 2.2,
        "impactScore": 3.4,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-55663",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-08-25T18:55:43.763697Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-08-25T19:16:51.060",
  "references": [
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/versatica/mediasoup/commit/9c1a90a8f9206b965e727d134846fb42df4980a7"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/versatica/mediasoup/pull/1829"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/versatica/mediasoup/releases/tag/3.20.6"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/versatica/mediasoup/security/advisories/GHSA-p7x2-g5cq-fhmq"
    },
    {
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "url": "https://github.com/versatica/mediasoup/security/advisories/GHSA-p7x2-g5cq-fhmq"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-345"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Primary"
    }
  ]
}



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