CVE-2026-39912

{
  "id": "CVE-2026-39912",
  "sourceIdentifier": "[email protected]",
  "published": "2026-04-09T19:16:25.920",
  "lastModified": "2026-10-26T21:10:00.170",
  "vulnStatus": "Deferred",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "V2Board 1.6.1 through 1.7.4 and Xboard through 0.1.9 expose authentication tokens in HTTP response bodies of the loginWithMailLink endpoint when the login_with_mail_link_enable feature is active. Unauthenticated attackers can POST to the loginWithMailLink endpoint with a known email address to receive the full authentication URL in the response, then exchange the token at the token2Login endpoint to obtain a valid bearer token with complete account access including admin privileges."
    },
    {
      "lang": "es",
      "value": "V2Board 1.6.1 hasta 1.7.4 y Xboard hasta 0.1.9 exponen tokens de autenticación en los cuerpos de respuesta HTTP del endpoint loginWithMailLink cuando la característica login_with_mail_link_enable está activa. Atacantes no autenticados pueden realizar una solicitud POST al endpoint loginWithMailLink con una dirección de correo electrónico conocida para recibir la URL de autenticación completa en la respuesta, luego intercambiar el token en el endpoint token2Login para obtener un token de portador válido con acceso completo a la cuenta, incluyendo privilegios de administrador."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "v2board",
          "product": "v2board",
          "defaultStatus": "unknown",
          "repo": "https://github.com/v2board/v2board",
          "packageURL": "pkg:github/v2board/v2board",
          "versions": [
            {
              "version": "1.6.1",
              "lessThanOrEqual": "1.7.4",
              "versionType": "semver",
              "status": "affected"
            },
            {
              "version": "bdb10bed32c5f37df2f0872c3cb354e9b7a293bd",
              "lessThanOrEqual": "0ca47622a50116d0ddd7ffb316b157afb57d25e8",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "cedar2025",
          "product": "Xboard",
          "defaultStatus": "unaffected",
          "repo": "https://github.com/cedar2025/Xboard",
          "packageURL": "pkg:github/cedar2025/Xboard",
          "versions": [
            {
              "version": "0",
              "lessThanOrEqual": "0.1.9",
              "versionType": "semver",
              "status": "affected"
            },
            {
              "version": "121511523f04882ec0c7447acd9b8ebcb8a47957",
              "versionType": "git",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV40": [
      {
        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "4.0",
          "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/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": 9.1,
          "baseSeverity": "CRITICAL",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "attackRequirements": "PRESENT",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "vulnConfidentialityImpact": "HIGH",
          "vulnIntegrityImpact": "HIGH",
          "vulnAvailabilityImpact": "NONE",
          "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"
        }
      }
    ],
    "cvssMetricV31": [
      {
        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N",
          "baseScore": 9.1,
          "baseSeverity": "CRITICAL",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "availabilityImpact": "NONE"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 5.2
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-04-10T20:16:59.517212Z",
          "id": "CVE-2026-39912",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-201"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://chocapikk.com/posts/2026/xboard-v2board-account-takeover/",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/cedar2025/Xboard/blob/1fe6531924cc1ec662a88b9ef725afcf78d660bc/app/Http/Controllers/V1/Passport/AuthController.php#L51",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/cedar2025/Xboard/blob/1fe6531924cc1ec662a88b9ef725afcf78d660bc/app/Services/Auth/MailLinkService.php#L49",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/cedar2025/Xboard/commit/121511523f04882ec0c7447acd9b8ebcb8a47957",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/cedar2025/Xboard/pull/873",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/v2board/v2board/blob/0ca47622a50116d0ddd7ffb316b157afb57d25e8/app/Http/Controllers/Passport/AuthController.php#L71",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/v2board/v2board/pull/981",
      "source": "[email protected]"
    },
    {
      "url": "https://www.vulncheck.com/advisories/v2board-xboard-authentication-token-exposure-via-loginwithmaillink",
      "source": "[email protected]"
    }
  ]
}