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CVE-2026-48599

Full vulnerability record from the local CVENow database.

Description

Authorization Bypass Through User-Controlled Key vulnerability in elixir-grpc grpc allows authenticated attackers to access or modify resources belonging to other users by smuggling a conflicting value for any path-bound field via the query string or request body. In 'Elixir.GRPC.Server.Transcode':map_request/5 (lib/grpc/server/transcode.ex), all three clauses use Map.merge/2 with path bindings as the first argument, giving them the lowest merge precedence. A request such as GET /users/me/profile?user_id=victim (or a POST with {"user_id": "victim"} when body: "*") yields a decoded protobuf struct where the path-bound field carries the attacker-supplied value rather than the router-extracted value. Any handler that uses the path-bound field for authorization, multi-tenancy scoping, or ownership checks is silently bypassed. This issue affects grpc: from 0.8.0 before 1.0.0.

Severity
HIGH
CVSS score
7.6 (v4.0)
Vulnerability status
Deferred
Source identifier
6b3ad84c-e1a6-4bf7-a703-f496b71e49db
Published
2026-06-15 23:16:45.377000
Last modified
2026-10-25 23:10:00.167000
View original CVE JSON 
{
  "id": "CVE-2026-48599",
  "sourceIdentifier": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
  "published": "2026-06-15T23:16:45.377",
  "lastModified": "2026-10-25T23:10:00.167",
  "vulnStatus": "Deferred",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Authorization Bypass Through User-Controlled Key vulnerability in elixir-grpc grpc allows authenticated attackers to access or modify resources belonging to other users by smuggling a conflicting value for any path-bound field via the query string or request body.\n\nIn 'Elixir.GRPC.Server.Transcode':map_request/5 (lib/grpc/server/transcode.ex), all three clauses use Map.merge/2 with path bindings as the first argument, giving them the lowest merge precedence. A request such as GET /users/me/profile?user_id=victim (or a POST with {\"user_id\": \"victim\"} when body: \"*\") yields a decoded protobuf struct where the path-bound field carries the attacker-supplied value rather than the router-extracted value. Any handler that uses the path-bound field for authorization, multi-tenancy scoping, or ownership checks is silently bypassed.\n\nThis issue affects grpc: from 0.8.0 before 1.0.0."
    },
    {
      "lang": "es",
      "value": "Vulnerabilidad de omisión de autorización a través de clave controlada por el usuario en elixir-grpc grpc permite a atacantes autenticados acceder o modificar recursos pertenecientes a otros usuarios mediante el contrabando de un valor conflictivo para cualquier campo ligado a la ruta a través de la cadena de consulta o el cuerpo de la solicitud.\n\nEn ’Elixir.GRPC.Server.Transcode’:map_request/5 (lib/grpc/server/transcode.ex), las tres cláusulas usan Map.merge/2 con las ligaduras de ruta como primer argumento, dándoles la menor precedencia de fusión. Una solicitud como GET /users/me/profile?user_id=victim (o un POST con {“user_id”: “victim”} cuando body: “*”) produce una estructura protobuf decodificada donde el campo ligado a la ruta lleva el valor proporcionado por el atacante en lugar del valor extraído por el router. Cualquier gestor que usa el campo ligado a la ruta para autorización, alcance de multi-tenencia o comprobaciones de propiedad es omitido silenciosamente.\n\nEste problema afecta a grpc desde 0.8.0 antes de 1.0.0."
    }
  ],
  "affected": [
    {
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
      "affectedData": [
        {
          "vendor": "elixir-grpc",
          "product": "grpc",
          "defaultStatus": "unaffected",
          "collectionURL": "https://repo.hex.pm",
          "packageName": "grpc",
          "cpes": [
            "cpe:2.3:a:elixir-grpc:grpc:*:*:*:*:*:*:*:*"
          ],
          "modules": [
            "'Elixir.GRPC.Server.Transcode'"
          ],
          "programFiles": [
            "lib/grpc/server/transcode.ex"
          ],
          "programRoutines": [
            {
              "name": "'Elixir.GRPC.Server.Transcode':map_request/5"
            }
          ],
          "repo": "https://github.com/elixir-grpc/grpc",
          "packageURL": "pkg:hex/grpc",
          "versions": [
            {
              "version": "0.8.0",
              "lessThan": "1.0.0",
              "versionType": "semver",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "elixir-grpc",
          "product": "grpc",
          "defaultStatus": "unaffected",
          "collectionURL": "https://github.com",
          "packageName": "elixir-grpc/grpc",
          "cpes": [
            "cpe:2.3:a:elixir-grpc:grpc:*:*:*:*:*:*:*:*"
          ],
          "modules": [
            "'Elixir.GRPC.Server.Transcode'"
          ],
          "programFiles": [
            "lib/grpc/server/transcode.ex"
          ],
          "programRoutines": [
            {
              "name": "'Elixir.GRPC.Server.Transcode':map_request/5"
            }
          ],
          "repo": "https://github.com/elixir-grpc/grpc",
          "packageURL": "pkg:github/elixir-grpc/grpc",
          "versions": [
            {
              "version": "8aaf3d3a8c4c7b08ac65e9c6f254e0d24da1d048",
              "lessThan": "33b6a095dbc91c6dee3c7b90893d7d74952e82e4",
              "versionType": "git",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV40": [
      {
        "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
        "type": "Secondary",
        "cvssData": {
          "version": "4.0",
          "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:L/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": 7.6,
          "baseSeverity": "HIGH",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "attackRequirements": "PRESENT",
          "privilegesRequired": "LOW",
          "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"
        }
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-06-16T14:45:46.288762Z",
          "id": "CVE-2026-48599",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-639"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://cna.erlef.org/cves/CVE-2026-48599.html",
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"
    },
    {
      "url": "https://github.com/elixir-grpc/grpc/commit/33b6a095dbc91c6dee3c7b90893d7d74952e82e4",
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"
    },
    {
      "url": "https://github.com/elixir-grpc/grpc/commit/8aaf3d3a8c4c7b08ac65e9c6f254e0d24da1d048",
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"
    },
    {
      "url": "https://github.com/elixir-grpc/grpc/security/advisories/GHSA-mwr4-5g34-j5cq",
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"
    },
    {
      "url": "https://osv.dev/vulnerability/EEF-CVE-2026-48599",
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"
    },
    {
      "url": "https://github.com/elixir-grpc/grpc/security/advisories/GHSA-mwr4-5g34-j5cq",
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"
    }
  ]
}