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CVE-2026-55666

Full vulnerability record from the local CVENow database.

Description

Rocket.Chat is an open-source, secure, fully customizable communications platform. Prior to 8.5.1, 8.4.4, 8.3.6, 8.2.6, 8.1.6, 8.0.7, and 7.10.13, in apps/meteor/app/apple/server/loginHandler.ts, handleIdentityToken parses a JWT issued by Apple during the OAuth flow. The try block checks for an email parameter. If the JWT does not contain an email address, the application falls back to accepting an arbitrary email value supplied directly in the request. Attackers are able to forge Apple JWTs that do not contain an email address and leverage this vulnerability to carry out account takeover attacks. This vulnerability is fixed in 8.5.1, 8.4.4, 8.3.6, 8.2.6, 8.1.6, 8.0.7, and 7.10.13.

Severity
CRITICAL
CVSS score
9.3 (v4.0)
Vulnerability status
Deferred
Source identifier
Published
2026-06-24 22:16:49.393000
Last modified
2026-10-25 23:10:00.167000
View original CVE JSON
{
  "id": "CVE-2026-55666",
  "sourceIdentifier": "[email protected]",
  "published": "2026-06-24T22:16:49.393",
  "lastModified": "2026-10-25T23:10:00.167",
  "vulnStatus": "Deferred",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Rocket.Chat is an open-source, secure, fully customizable communications platform. Prior to 8.5.1, 8.4.4, 8.3.6, 8.2.6, 8.1.6, 8.0.7, and 7.10.13, in apps/meteor/app/apple/server/loginHandler.ts, handleIdentityToken parses a JWT issued by Apple during the OAuth flow. The try block checks for an email parameter. If the JWT does not contain an email address, the application falls back to accepting an arbitrary email value supplied directly in the request. Attackers are able to forge Apple JWTs that do not contain an email address and leverage this vulnerability to carry out account takeover attacks. This vulnerability is fixed in 8.5.1, 8.4.4, 8.3.6, 8.2.6, 8.1.6, 8.0.7, and 7.10.13."
    },
    {
      "lang": "es",
      "value": "Rocket.Chat es una plataforma de comunicaciones de código abierto, segura y totalmente personalizable. Antes de las versiones 8.5.1, 8.4.4, 8.3.6, 8.2.6, 8.1.6, 8.0.7 y 7.10.13, en apps/meteor/app/apple/servidor/loginHandler.ts, handleIdentityToken analiza un JWT emitido por Apple durante el flujo de OAuth. El bloque try verifica un parámetro de correo electrónico. Si el JWT no contiene una dirección de correo electrónico, la aplicación recurre a aceptar un valor de correo electrónico arbitrario suministrado directamente en la solicitud. Los atacantes pueden falsificar JWT de Apple que no contienen una dirección de correo electrónico y aprovechar esta vulnerabilidad para llevar a cabo ataques de toma de control de cuentas. Esta vulnerabilidad está corregida en las versiones 8.5.1, 8.4.4, 8.3.6, 8.2.6, 8.1.6, 8.0.7 y 7.10.13."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "RocketChat",
          "product": "Rocket.Chat",
          "versions": [
            {
              "version": ">= 8.5.0-rc.0, < 8.5.1",
              "status": "affected"
            },
            {
              "version": ">= 8.4.0-rc.0, < 8.4.4",
              "status": "affected"
            },
            {
              "version": ">= 8.3.0-rc.0, < 8.3.6",
              "status": "affected"
            },
            {
              "version": ">= 8.2.0-rc.0, < 8.2.6",
              "status": "affected"
            },
            {
              "version": ">= 8.1.0-rc.0, < 8.1.6",
              "status": "affected"
            },
            {
              "version": ">= 7.11.0-rc.0, < 8.0.7",
              "status": "affected"
            },
            {
              "version": "< 7.10.13",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV40": [
      {
        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "4.0",
          "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
          "baseScore": 9.3,
          "baseSeverity": "CRITICAL",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "attackRequirements": "NONE",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "vulnConfidentialityImpact": "HIGH",
          "vulnIntegrityImpact": "HIGH",
          "vulnAvailabilityImpact": "HIGH",
          "subConfidentialityImpact": "NONE",
          "subIntegrityImpact": "NONE",
          "subAvailabilityImpact": "NONE",
          "exploitMaturity": "NOT_DEFINED",
          "confidentialityRequirement": "NOT_DEFINED",
          "integrityRequirement": "NOT_DEFINED",
          "availabilityRequirement": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "valueDensity": "NOT_DEFINED",
          "vulnerabilityResponseEffort": "NOT_DEFINED",
          "providerUrgency": "NOT_DEFINED"
        }
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-06-26T03:55:30.444148Z",
          "id": "CVE-2026-55666",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-287"
        },
        {
          "lang": "en",
          "value": "CWE-288"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://github.com/RocketChat/Rocket.Chat/security/advisories/GHSA-wx3c-76rf-wpwf",
      "source": "[email protected]"
    }
  ]
}