CVE-2026-56388

{
  "id": "CVE-2026-56388",
  "sourceIdentifier": "[email protected]",
  "published": "2026-10-21T12:17:21.680",
  "lastModified": "2026-10-30T14:17:06.653",
  "vulnStatus": "Deferred",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "The Redis server command parser in Apache bRPC accepts an empty RESP array as a command header. A remote unauthenticated attacker who can reach a bRPC server with Redis service enabled can send an empty array header followed by a bulk string, causing an out-of-bounds write in the parser and crashing the process.\n\nRoot Cause:\nRedisCommandParser::ConsumeImpl rejected negative RESP array counts but accepted zero. It resized the command argument vector to zero elements and continued parsing. When a following bulk string was parsed, the only index guard was a CHECK. In configurations where fatal logs do not abort immediately, execution could continue and write to _args[0] even though the vector was empty.\n\nAffected Scenarios:\nDeployments that enable ServerOptions.redis_service and accept Redis protocol traffic from untrusted clients. The issue is reached during parsing before command handling or authentication.\n\nHow to Fix:\n1. Upgrade bRPC to version 1.18.0, which fixes this issue.\n2. Apply this patch:  https://github.com/apache/brpc/pull/3354 \n\nNote:\nThe fix rejects empty RESP arrays as invalid Redis commands and replaces the internal index CHECK with an explicit parse error so malformed command streams cannot fall through to an indexed vector write."
    },
    {
      "lang": "es",
      "value": "El analizador de comandos del servidor Redis en Apache bRPC acepta un arreglo RESP vacío como encabezado de comando. Un atacante remoto no autenticado que pueda alcanzar un servidor bRPC con el servicio Redis habilitado puede enviar un encabezado de arreglo vacío seguido de una cadena bulk, provocando una escritura fuera de límites en el analizador y el bloqueo del proceso.\\n\\nCausa raíz:\\nRedisCommandParser::ConsumeImpl rechazó recuentos de arreglos RESP negativos pero aceptó cero. Redimensionó el vector de argumentos del comando a cero elementos y continuó el análisis. Cuando se analizó una cadena bulk posterior, la única protección de índice era un CHECK. En configuraciones donde los registros fatales no abortan inmediatamente, la ejecución podría continuar y escribir en _args[0] aunque el vector estuviera vacío.\\n\\nEscenarios afectados:\\nImplementaciones que habilitan ServerOptions.redis_service y aceptan tráfico del protocolo Redis de clientes no confiables. El problema se alcanza durante el análisis antes del manejo del comando o la autenticación.\\n\\nCómo solucionar:\\n1. Actualizar bRPC a la versión 1.18.0, que corrige este problema.\\n2. Aplicar este parche: https://github.com/apache/brpc/pull/3354\\n\\nNota:\\nLa corrección rechaza los arreglos RESP vacíos como comandos Redis no válidos y reemplaza el CHECK interno de índice por un error de análisis explícito, de modo que los flujos de comandos malformados no puedan pasar a una escritura en un vector indexado."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "Apache Software Foundation",
          "product": "Apache bRPC",
          "defaultStatus": "unaffected",
          "collectionURL": "https://github.com",
          "packageName": "apache/brpc",
          "packageURL": "pkg:github/apache/brpc",
          "versions": [
            {
              "version": "0",
              "lessThan": "1.18.0",
              "versionType": "semver",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H",
          "baseScore": 9.1,
          "baseSeverity": "CRITICAL",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "HIGH",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 5.2
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-10-30T13:57:39.892176Z",
          "id": "CVE-2026-56388",
          "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-252"
        },
        {
          "lang": "en",
          "value": "CWE-617"
        },
        {
          "lang": "en",
          "value": "CWE-787"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://lists.apache.org/thread/2pf15ojj0vr7rtx95677kgtl1mx3gdgb",
      "source": "[email protected]"
    }
  ]
}