Vulnerability-Lookup

CVE-2026-74757 (GCVE-0-2026-74757)

Vulnerability from cvelistv5 – Published: 2026-10-21 11:46 – Updated: 2026-10-26 13:40

Title

Apache bRPC: Uncontrolled Memory Allocation via Malicious mcpack Array Item Count

Summary

Uncontrolled resource allocation in the mcpack2pb component in Apache bRPC (version < 1.18.0) on all platforms allows remote attackers to make the server allocate a large amount of memory via sending a crafted mcpack request with a huge array item count. Root Cause: The bRPC mcpack2pb parser trusts the item count stored in the mcpack array header without validating it against the actual payload size. The code generated by the mcpack2pb protoc plugin uses this count to preallocate memory for repeated protobuf fields via Reserve(). A malformed request declaring item_count = 0x7fffffff can force the server to preallocate about 16GB of virtual memory, which may abort the process (SIGABRT) on memory-constrained hosts. Affected Scenarios: Use a bRPC server that wires a NsheadService to UbrpcMcpack2Adaptor (the Baidu ubrpc deployment pattern) and parses requests with code generated by the mcpack2pb protoc plugin. The request body is parsed before authentication. How to Fix: (Choose one of the following options) 1. Upgrade bRPC to version 1.18.0, which fixes this issue. 2. Apply this patch: https://github.com/apache/brpc/pull/3451 Note: No matter which option you choose, you should know that the fix caps the array item count to the remaining bytes of the array payload.

Severity

7.5 (High)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

SSVC

Exploitation: none Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-10-26 13:39 UTC

CWE

CWE-770 - Allocation of Resources Without Limits or Throttling

Assigner

apache CNA under the mitre root

CNA scorecard B 76/100 over 1112 records in the last 180 days details

References

1 reference

URL	Tags
https://lists.apache.org/thread/2pf15ojj0vr7rtx95…	vendor-advisory

Impacted products

1 product

Vendor	Product	Version	CPE status
Apache Software Foundation	Apache bRPC	Affected: 0 , < 1.18.0 (semver)	guessed

Credits

Feng Zhijie (Dopamine)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "LOW",
              "attackVector": "NETWORK",
              "availabilityImpact": "HIGH",
              "baseScore": 7.5,
              "baseSeverity": "HIGH",
              "confidentialityImpact": "NONE",
              "integrityImpact": "NONE",
              "privilegesRequired": "NONE",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2026-74757",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-10-26T13:39:58.132230Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-10-26T13:40:04.776Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "collectionURL": "https://github.com",
          "defaultStatus": "unaffected",
          "packageName": "apache/brpc",
          "packageURL": "pkg:github/apache/brpc",
          "product": "Apache bRPC",
          "vendor": "Apache Software Foundation",
          "versions": [
            {
              "lessThan": "1.18.0",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "Feng Zhijie (Dopamine)"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "Uncontrolled resource allocation in the mcpack2pb component in Apache bRPC (version \u0026lt; 1.18.0) on all platforms allows remote attackers to make the server allocate a large amount of memory via sending a crafted mcpack request with a huge array item count.\u003cbr\u003e\u003cbr\u003eRoot Cause:\u003cbr\u003eThe bRPC\u0026nbsp;mcpack2pb parser trusts the item count stored in the mcpack array header without validating it against the actual payload size. The code generated by the mcpack2pb protoc plugin uses this count to preallocate memory for repeated protobuf fields via Reserve(). A malformed request declaring item_count = 0x7fffffff can force the server to preallocate about 16GB of virtual memory, which may abort the process (SIGABRT) on memory-constrained hosts.\u003cbr\u003e\u003cbr\u003eAffected Scenarios:\u003cbr\u003eUse a bRPC server that wires a NsheadService to UbrpcMcpack2Adaptor (the Baidu ubrpc deployment pattern) and parses requests with code generated by the mcpack2pb protoc plugin. The request body is parsed before authentication.\u003cbr\u003e\u003cbr\u003eHow to Fix:\u003cbr\u003e(Choose one of the following options)\u003cbr\u003e1. Upgrade bRPC to version 1.18.0, which fixes this issue.\u003cbr\u003e\u003cspan\u003e2. Apply this patch: \u003c/span\u003e\u003ca target=\"_blank\" rel=\"nofollow\" href=\"https://github.com/apache/brpc/pull/3451\"\u003ehttps://github.com/apache/brpc/pull/3451\u003c/a\u003e\u003cbr\u003e\u003cbr\u003eNote:\u003cbr\u003eNo matter which option \u003cspan\u003eyou choose\u003c/span\u003e, you should know that the fix caps the array item count to the remaining bytes of the array payload."
            }
          ],
          "value": "Uncontrolled resource allocation in the mcpack2pb component in Apache bRPC (version \u003c 1.18.0) on all platforms allows remote attackers to make the server allocate a large amount of memory via sending a crafted mcpack request with a huge array item count.\n\nRoot Cause:\nThe bRPC\u00a0mcpack2pb parser trusts the item count stored in the mcpack array header without validating it against the actual payload size. The code generated by the mcpack2pb protoc plugin uses this count to preallocate memory for repeated protobuf fields via Reserve(). A malformed request declaring item_count = 0x7fffffff can force the server to preallocate about 16GB of virtual memory, which may abort the process (SIGABRT) on memory-constrained hosts.\n\nAffected Scenarios:\nUse a bRPC server that wires a NsheadService to UbrpcMcpack2Adaptor (the Baidu ubrpc deployment pattern) and parses requests with code generated by the mcpack2pb protoc plugin. The request body is parsed before authentication.\n\nHow to Fix:\n(Choose one of the following options)\n1. Upgrade bRPC to version 1.18.0, which fixes this issue.\n2. Apply this patch:  https://github.com/apache/brpc/pull/3451 \n\nNote:\nNo matter which option you choose, you should know that the fix caps the array item count to the remaining bytes of the array payload."
        }
      ],
      "metrics": [
        {
          "other": {
            "content": {
              "text": "high"
            },
            "type": "Textual description of severity"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-770",
              "description": "CWE-770 Allocation of Resources Without Limits or Throttling",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-21T11:46:17.285Z",
        "orgId": "f0158376-9dc2-43b6-827c-5f631a4d8d09",
        "shortName": "apache"
      },
      "references": [
        {
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://lists.apache.org/thread/2pf15ojj0vr7rtx95677kgtl1mx3gdgb"
        }
      ],
      "source": {
        "discovery": "EXTERNAL"
      },
      "title": "Apache bRPC: Uncontrolled Memory Allocation via Malicious mcpack Array Item Count",
      "x_generator": {
        "engine": "Vulnogram 0.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "f0158376-9dc2-43b6-827c-5f631a4d8d09",
    "assignerShortName": "apache",
    "cveId": "CVE-2026-74757",
    "datePublished": "2026-10-21T11:46:17.285Z",
    "dateReserved": "2026-08-15T07:51:09.501Z",
    "dateUpdated": "2026-10-26T13:40:04.776Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-74757",
      "date": "2026-11-04",
      "epss": "0.0063",
      "percentile": "0.50343"
    },
    "nvd": {
      "cve": {
        "affected": [
          {
            "affectedData": [
              {
                "collectionURL": "https://github.com",
                "defaultStatus": "unaffected",
                "packageName": "apache/brpc",
                "packageURL": "pkg:github/apache/brpc",
                "product": "Apache bRPC",
                "vendor": "Apache Software Foundation",
                "versions": [
                  {
                    "lessThan": "1.18.0",
                    "status": "affected",
                    "version": "0",
                    "versionType": "semver"
                  }
                ]
              }
            ],
            "source": "security@apache.org"
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "Uncontrolled resource allocation in the mcpack2pb component in Apache bRPC (version \u003c 1.18.0) on all platforms allows remote attackers to make the server allocate a large amount of memory via sending a crafted mcpack request with a huge array item count.\n\nRoot Cause:\nThe bRPC\u00a0mcpack2pb parser trusts the item count stored in the mcpack array header without validating it against the actual payload size. The code generated by the mcpack2pb protoc plugin uses this count to preallocate memory for repeated protobuf fields via Reserve(). A malformed request declaring item_count = 0x7fffffff can force the server to preallocate about 16GB of virtual memory, which may abort the process (SIGABRT) on memory-constrained hosts.\n\nAffected Scenarios:\nUse a bRPC server that wires a NsheadService to UbrpcMcpack2Adaptor (the Baidu ubrpc deployment pattern) and parses requests with code generated by the mcpack2pb protoc plugin. The request body is parsed before authentication.\n\nHow to Fix:\n(Choose one of the following options)\n1. Upgrade bRPC to version 1.18.0, which fixes this issue.\n2. Apply this patch:  https://github.com/apache/brpc/pull/3451 \n\nNote:\nNo matter which option you choose, you should know that the fix caps the array item count to the remaining bytes of the array payload."
          },
          {
            "lang": "es",
            "value": "Asignaci\u00f3n descontrolada de recursos en el componente mcpack2pb de Apache bRPC (versiones anteriores a la 1.18.0) en todas las plataformas permite a atacantes remotos hacer que el servidor reserve una gran cantidad de memoria mediante el env\u00edo de una solicitud mcpack manipulada con un recuento de elementos de matriz enorme.\\n\\nCausa ra\u00edz:\\nEl analizador mcpack2pb de bRPC conf\u00eda en el recuento de elementos almacenado en el encabezado del arreglo mcpack sin validarlo contra el tama\u00f1o real de la carga \u00fatil. El c\u00f3digo generado por el plugin mcpack2pb protoc utiliza este recuento para preasignar memoria para campos protobuf repetidos mediante Reserve(). Una solicitud malformada que declare item_count = 0x7fffffff puede obligar al servidor a preasignar aproximadamente 16?GB de memoria virtual, lo que puede abortar el proceso (SIGABRT) en hosts con recursos de memoria limitados.\\n\\nEscenarios afectados:\\nUso de un servidor bRPC que conecta un NsheadService a UbrpcMcpack2Adaptor (el patr\u00f3n de despliegue de Baidu ubrpc) y analiza solicitudes con c\u00f3digo generado por el plugin mcpack2pb protoc. El cuerpo de la solicitud se analiza antes de la autenticaci\u00f3n.\\n\\nC\u00f3mo corregir:\\n(Elija una de las siguientes opciones)\\n1. Actualice bRPC a la versi\u00f3n 1.18.0, que corrige este problema.\\n2. Aplique este parche: https://github.com/apache/brpc/pull/3451\\n\\nNota:\\nIndependientemente de la opci\u00f3n que elija, debe saber que la correcci\u00f3n limita el recuento de elementos del arreglo a los bytes restantes de la carga \u00fatil del arreglo."
          }
        ],
        "id": "CVE-2026-74757",
        "lastModified": "2026-10-26T20:10:00.160",
        "metrics": {
          "cvssMetricV31": [
            {
              "cvssData": {
                "attackComplexity": "LOW",
                "attackVector": "NETWORK",
                "availabilityImpact": "HIGH",
                "baseScore": 7.5,
                "baseSeverity": "HIGH",
                "confidentialityImpact": "NONE",
                "integrityImpact": "NONE",
                "privilegesRequired": "NONE",
                "scope": "UNCHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
                "version": "3.1"
              },
              "exploitabilityScore": 3.9,
              "impactScore": 3.6,
              "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "type": "Secondary"
            }
          ],
          "ssvcV203": [
            {
              "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "ssvcData": {
                "id": "CVE-2026-74757",
                "options": [
                  {
                    "exploitation": "none"
                  },
                  {
                    "automatable": "yes"
                  },
                  {
                    "technicalImpact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-10-26T13:39:58.132230Z",
                "version": "2.0.3"
              }
            }
          ]
        },
        "published": "2026-10-21T12:17:22.700",
        "references": [
          {
            "source": "security@apache.org",
            "url": "https://lists.apache.org/thread/2pf15ojj0vr7rtx95677kgtl1mx3gdgb"
          }
        ],
        "sourceIdentifier": "security@apache.org",
        "vulnStatus": "Deferred",
        "weaknesses": [
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-770"
              }
            ],
            "source": "security@apache.org",
            "type": "Secondary"
          }
        ]
      }
    },
    "vulnrichment": {
      "containers": {
        "adp": [
          {
            "metrics": [
              {
                "cvssV3_1": {
                  "attackComplexity": "LOW",
                  "attackVector": "NETWORK",
                  "availabilityImpact": "HIGH",
                  "baseScore": 7.5,
                  "baseSeverity": "HIGH",
                  "confidentialityImpact": "NONE",
                  "integrityImpact": "NONE",
                  "privilegesRequired": "NONE",
                  "scope": "UNCHANGED",
                  "userInteraction": "NONE",
                  "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
                  "version": "3.1"
                }
              },
              {
                "other": {
                  "content": {
                    "id": "CVE-2026-74757",
                    "options": [
                      {
                        "Exploitation": "none"
                      },
                      {
                        "Automatable": "yes"
                      },
                      {
                        "Technical Impact": "partial"
                      }
                    ],
                    "role": "CISA Coordinator",
                    "timestamp": "2026-10-26T13:39:58.132230Z",
                    "version": "2.0.3"
                  },
                  "type": "ssvc"
                }
              }
            ],
            "providerMetadata": {
              "dateUpdated": "2026-10-26T13:39:54.461Z",
              "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "shortName": "CISA-ADP"
            },
            "title": "CISA ADP Vulnrichment"
          }
        ],
        "cna": {
          "affected": [
            {
              "collectionURL": "https://github.com",
              "defaultStatus": "unaffected",
              "packageName": "apache/brpc",
              "packageURL": "pkg:github/apache/brpc",
              "product": "Apache bRPC",
              "vendor": "Apache Software Foundation",
              "versions": [
                {
                  "lessThan": "1.18.0",
                  "status": "affected",
                  "version": "0",
                  "versionType": "semver"
                }
              ]
            }
          ],
          "credits": [
            {
              "lang": "en",
              "type": "finder",
              "value": "Feng Zhijie (Dopamine)"
            }
          ],
          "descriptions": [
            {
              "lang": "en",
              "supportingMedia": [
                {
                  "base64": false,
                  "type": "text/html",
                  "value": "Uncontrolled resource allocation in the mcpack2pb component in Apache bRPC (version \u0026lt; 1.18.0) on all platforms allows remote attackers to make the server allocate a large amount of memory via sending a crafted mcpack request with a huge array item count.\u003cbr\u003e\u003cbr\u003eRoot Cause:\u003cbr\u003eThe bRPC\u0026nbsp;mcpack2pb parser trusts the item count stored in the mcpack array header without validating it against the actual payload size. The code generated by the mcpack2pb protoc plugin uses this count to preallocate memory for repeated protobuf fields via Reserve(). A malformed request declaring item_count = 0x7fffffff can force the server to preallocate about 16GB of virtual memory, which may abort the process (SIGABRT) on memory-constrained hosts.\u003cbr\u003e\u003cbr\u003eAffected Scenarios:\u003cbr\u003eUse a bRPC server that wires a NsheadService to UbrpcMcpack2Adaptor (the Baidu ubrpc deployment pattern) and parses requests with code generated by the mcpack2pb protoc plugin. The request body is parsed before authentication.\u003cbr\u003e\u003cbr\u003eHow to Fix:\u003cbr\u003e(Choose one of the following options)\u003cbr\u003e1. Upgrade bRPC to version 1.18.0, which fixes this issue.\u003cbr\u003e\u003cspan\u003e2. Apply this patch: \u003c/span\u003e\u003ca target=\"_blank\" rel=\"nofollow\" href=\"https://github.com/apache/brpc/pull/3451\"\u003ehttps://github.com/apache/brpc/pull/3451\u003c/a\u003e\u003cbr\u003e\u003cbr\u003eNote:\u003cbr\u003eNo matter which option \u003cspan\u003eyou choose\u003c/span\u003e, you should know that the fix caps the array item count to the remaining bytes of the array payload."
                }
              ],
              "value": "Uncontrolled resource allocation in the mcpack2pb component in Apache bRPC (version \u003c 1.18.0) on all platforms allows remote attackers to make the server allocate a large amount of memory via sending a crafted mcpack request with a huge array item count.\n\nRoot Cause:\nThe bRPC\u00a0mcpack2pb parser trusts the item count stored in the mcpack array header without validating it against the actual payload size. The code generated by the mcpack2pb protoc plugin uses this count to preallocate memory for repeated protobuf fields via Reserve(). A malformed request declaring item_count = 0x7fffffff can force the server to preallocate about 16GB of virtual memory, which may abort the process (SIGABRT) on memory-constrained hosts.\n\nAffected Scenarios:\nUse a bRPC server that wires a NsheadService to UbrpcMcpack2Adaptor (the Baidu ubrpc deployment pattern) and parses requests with code generated by the mcpack2pb protoc plugin. The request body is parsed before authentication.\n\nHow to Fix:\n(Choose one of the following options)\n1. Upgrade bRPC to version 1.18.0, which fixes this issue.\n2. Apply this patch:  https://github.com/apache/brpc/pull/3451 \n\nNote:\nNo matter which option you choose, you should know that the fix caps the array item count to the remaining bytes of the array payload."
            }
          ],
          "metrics": [
            {
              "other": {
                "content": {
                  "text": "high"
                },
                "type": "Textual description of severity"
              },
              "scenarios": [
                {
                  "lang": "en",
                  "value": "GENERAL"
                }
              ]
            }
          ],
          "problemTypes": [
            {
              "descriptions": [
                {
                  "cweId": "CWE-770",
                  "description": "CWE-770 Allocation of Resources Without Limits or Throttling",
                  "lang": "en",
                  "type": "CWE"
                }
              ]
            }
          ],
          "providerMetadata": {
            "dateUpdated": "2026-10-21T11:46:17.285Z",
            "orgId": "f0158376-9dc2-43b6-827c-5f631a4d8d09",
            "shortName": "apache"
          },
          "references": [
            {
              "tags": [
                "vendor-advisory"
              ],
              "url": "https://lists.apache.org/thread/2pf15ojj0vr7rtx95677kgtl1mx3gdgb"
            }
          ],
          "source": {
            "discovery": "EXTERNAL"
          },
          "title": "Apache bRPC: Uncontrolled Memory Allocation via Malicious mcpack Array Item Count",
          "x_generator": {
            "engine": "Vulnogram 0.2.0"
          }
        }
      },
      "cveMetadata": {
        "assignerOrgId": "f0158376-9dc2-43b6-827c-5f631a4d8d09",
        "assignerShortName": "apache",
        "cveId": "CVE-2026-74757",
        "datePublished": "2026-10-21T11:46:17.285Z",
        "dateReserved": "2026-08-15T07:51:09.501Z",
        "dateUpdated": "2026-10-26T13:40:04.776Z",
        "state": "PUBLISHED"
      },
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}

FKIE_CVE-2026-74757

Vulnerability from fkie_nvd - Published: 2026-10-21 12:17 - Updated: 2026-10-26 20:10

Severity

7.5 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Summary

References

	URL	Tags
	security@apache.org	https://lists.apache.org/thread/2pf15ojj0vr7rtx95677kgtl1mx3gdgb

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "collectionURL": "https://github.com",
          "defaultStatus": "unaffected",
          "packageName": "apache/brpc",
          "packageURL": "pkg:github/apache/brpc",
          "product": "Apache bRPC",
          "vendor": "Apache Software Foundation",
          "versions": [
            {
              "lessThan": "1.18.0",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "source": "security@apache.org"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Uncontrolled resource allocation in the mcpack2pb component in Apache bRPC (version \u003c 1.18.0) on all platforms allows remote attackers to make the server allocate a large amount of memory via sending a crafted mcpack request with a huge array item count.\n\nRoot Cause:\nThe bRPC\u00a0mcpack2pb parser trusts the item count stored in the mcpack array header without validating it against the actual payload size. The code generated by the mcpack2pb protoc plugin uses this count to preallocate memory for repeated protobuf fields via Reserve(). A malformed request declaring item_count = 0x7fffffff can force the server to preallocate about 16GB of virtual memory, which may abort the process (SIGABRT) on memory-constrained hosts.\n\nAffected Scenarios:\nUse a bRPC server that wires a NsheadService to UbrpcMcpack2Adaptor (the Baidu ubrpc deployment pattern) and parses requests with code generated by the mcpack2pb protoc plugin. The request body is parsed before authentication.\n\nHow to Fix:\n(Choose one of the following options)\n1. Upgrade bRPC to version 1.18.0, which fixes this issue.\n2. Apply this patch:  https://github.com/apache/brpc/pull/3451 \n\nNote:\nNo matter which option you choose, you should know that the fix caps the array item count to the remaining bytes of the array payload."
    },
    {
      "lang": "es",
      "value": "Asignaci\u00f3n descontrolada de recursos en el componente mcpack2pb de Apache bRPC (versiones anteriores a la 1.18.0) en todas las plataformas permite a atacantes remotos hacer que el servidor reserve una gran cantidad de memoria mediante el env\u00edo de una solicitud mcpack manipulada con un recuento de elementos de matriz enorme.\\n\\nCausa ra\u00edz:\\nEl analizador mcpack2pb de bRPC conf\u00eda en el recuento de elementos almacenado en el encabezado del arreglo mcpack sin validarlo contra el tama\u00f1o real de la carga \u00fatil. El c\u00f3digo generado por el plugin mcpack2pb protoc utiliza este recuento para preasignar memoria para campos protobuf repetidos mediante Reserve(). Una solicitud malformada que declare item_count = 0x7fffffff puede obligar al servidor a preasignar aproximadamente 16?GB de memoria virtual, lo que puede abortar el proceso (SIGABRT) en hosts con recursos de memoria limitados.\\n\\nEscenarios afectados:\\nUso de un servidor bRPC que conecta un NsheadService a UbrpcMcpack2Adaptor (el patr\u00f3n de despliegue de Baidu ubrpc) y analiza solicitudes con c\u00f3digo generado por el plugin mcpack2pb protoc. El cuerpo de la solicitud se analiza antes de la autenticaci\u00f3n.\\n\\nC\u00f3mo corregir:\\n(Elija una de las siguientes opciones)\\n1. Actualice bRPC a la versi\u00f3n 1.18.0, que corrige este problema.\\n2. Aplique este parche: https://github.com/apache/brpc/pull/3451\\n\\nNota:\\nIndependientemente de la opci\u00f3n que elija, debe saber que la correcci\u00f3n limita el recuento de elementos del arreglo a los bytes restantes de la carga \u00fatil del arreglo."
    }
  ],
  "id": "CVE-2026-74757",
  "lastModified": "2026-10-26T20:10:00.160",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 7.5,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 3.6,
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-74757",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-10-26T13:39:58.132230Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-10-21T12:17:22.700",
  "references": [
    {
      "source": "security@apache.org",
      "url": "https://lists.apache.org/thread/2pf15ojj0vr7rtx95677kgtl1mx3gdgb"
    }
  ],
  "sourceIdentifier": "security@apache.org",
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-770"
        }
      ],
      "source": "security@apache.org",
      "type": "Secondary"
    }
  ]
}

GHSA-PX5F-Q4RM-R7JP

Vulnerability from github – Published: 2026-10-21 12:31 – Updated: 2026-10-26 15:34

Details

Root Cause: The bRPC mcpack2pb parser trusts the item count stored in the mcpack array header without validating it against the actual payload size. The code generated by the mcpack2pb protoc plugin uses this count to preallocate memory for repeated protobuf fields via Reserve(). A malformed request declaring item_count = 0x7fffffff can force the server to preallocate about 16GB of virtual memory, which may abort the process (SIGABRT) on memory-constrained hosts.

Affected Scenarios: Use a bRPC server that wires a NsheadService to UbrpcMcpack2Adaptor (the Baidu ubrpc deployment pattern) and parses requests with code generated by the mcpack2pb protoc plugin. The request body is parsed before authentication.

How to Fix: (Choose one of the following options) 1. Upgrade bRPC to version 1.18.0, which fixes this issue. 2. Apply this patch: https://github.com/apache/brpc/pull/3451

Note: No matter which option you choose, you should know that the fix caps the array item count to the remaining bytes of the array payload.

Severity

7.5 (High)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Show details on source website

JSON

To clipboard

{
  "affected": [],
  "aliases": [
    "CVE-2026-74757"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-770"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-10-21T12:17:22Z",
    "severity": "HIGH"
  },
  "details": "Uncontrolled resource allocation in the mcpack2pb component in Apache bRPC (version \u003c 1.18.0) on all platforms allows remote attackers to make the server allocate a large amount of memory via sending a crafted mcpack request with a huge array item count.\n\nRoot Cause:\nThe bRPC\u00a0mcpack2pb parser trusts the item count stored in the mcpack array header without validating it against the actual payload size. The code generated by the mcpack2pb protoc plugin uses this count to preallocate memory for repeated protobuf fields via Reserve(). A malformed request declaring item_count = 0x7fffffff can force the server to preallocate about 16GB of virtual memory, which may abort the process (SIGABRT) on memory-constrained hosts.\n\nAffected Scenarios:\nUse a bRPC server that wires a NsheadService to UbrpcMcpack2Adaptor (the Baidu ubrpc deployment pattern) and parses requests with code generated by the mcpack2pb protoc plugin. The request body is parsed before authentication.\n\nHow to Fix:\n(Choose one of the following options)\n1. Upgrade bRPC to version 1.18.0, which fixes this issue.\n2. Apply this patch:  https://github.com/apache/brpc/pull/3451 \n\nNote:\nNo matter which option you choose, you should know that the fix caps the array item count to the remaining bytes of the array payload.",
  "id": "GHSA-px5f-q4rm-r7jp",
  "modified": "2026-10-26T15:34:21Z",
  "published": "2026-10-21T12:31:11Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-74757"
    },
    {
      "type": "WEB",
      "url": "https://lists.apache.org/thread/2pf15ojj0vr7rtx95677kgtl1mx3gdgb"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

Order JSON

How durations are calculated

Following the VTEM framework (Black Hat USA 2015), time to patch starts when the vendor or a coordinator was informed, total time to patch at discovery, and disclosure to patch at public disclosure; vendor response time runs from the report to its acknowledgement. Time to exploit and time unpatched start at the earliest discovery or report, falling back to public disclosure. Unpatched time ends at the first recorded patch, or the calculation time when no patch is recorded. Exploitation to patch shows the interval between those two events; a published proof of concept is a public exploit, not exploitation.

Each result shows its source dates. A negative interval means the end event came first; when date-only inputs leave the order open, the result says so. Date-only inputs are approximate. The earliest evidence wins: KEV report dates and sightings are labelled as such. Records describing another vulnerability are listed but never calculated from, and a PoC alone does not establish exploitation. Missing patch evidence does not prove that no patch exists. Filters below change the event list only.

Publication & reservation Sightings KEV catalogs Other timestamps

Loading timeline…

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

Action not permitted

CVE-2026-74757 (GCVE-0-2026-74757)

FKIE_CVE-2026-74757

GHSA-PX5F-Q4RM-R7JP

Tags

Sightings

Nomenclature

Vulnerability timeline

Related by attack behaviour