CVE-2026-19874 (GCVE-0-2026-19874)

Vulnerability from cvelistv5 – Published: 2026-08-24 15:02 – Updated: 2026-08-24 20:04
VLAI
Title
Konami's Metal Gear Online 3 contains a heap-based buffer overflow
Summary
A heap-based buffer overflow vulnerability exists in Konami's Metal Gear Online 3, originating from improper validation of lobby data fields related to kicked players. The affected function processes a list of kicked player identifiers using the lobby data key "kick_num" to determine the number of entries, and individual kicked player IDs supplied via keys in the format "kicked_id_%i". The function does not validate that "kick_num" falls within the expected bounds. The game design limits matches to a maximum of 16 players, and the corresponding buffer for storing kicked player IDs is sized accordingly. If "kick_num" exceeds this limit, the function continues writing the provided player IDs past the end of the intended buffer and into adjacent memory regions. These adjacent regions contain Steam callback handler structures responsible for processing lobby data updates, lobby messages, and other related events. By supplying an oversized "kick_num" value and appropriate "kicked_id_%i" fields, an attacker can overwrite fields within the callback handler structures, including function pointers and callback argument values. Successful exploitation may enable control-flow hijacking, potentially allowing arbitrary code execution within the game process.
Severity
9.1 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
SSVC
Exploitation: none Automatable: no Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-08-24 20:03 UTC
CWE
  • CWE-122 - Heap-based Buffer Overflow
Assigner
certcc CNA under the mitre root
CNA scorecard E 42/100 over 153 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
Konami Metal Gear Online 3 Affected: 1.1.2.8
guessed Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2026-08-24T16:11:06.391Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "url": "https://www.kb.cert.org/vuls/id/728712"
          }
        ],
        "title": "CVE Program Container"
      },
      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "LOW",
              "attackVector": "NETWORK",
              "availabilityImpact": "HIGH",
              "baseScore": 9.1,
              "baseSeverity": "CRITICAL",
              "confidentialityImpact": "NONE",
              "integrityImpact": "HIGH",
              "privilegesRequired": "NONE",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2026-19874",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-08-24T20:03:35.495374Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "problemTypes": [
          {
            "descriptions": [
              {
                "cweId": "CWE-122",
                "description": "CWE-122 Heap-based Buffer Overflow",
                "lang": "en",
                "type": "CWE"
              }
            ]
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-08-24T20:04:13.828Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "Metal Gear Online 3",
          "vendor": "Konami",
          "versions": [
            {
              "status": "affected",
              "version": "1.1.2.8"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "A heap-based buffer overflow vulnerability exists in Konami\u0027s Metal Gear Online 3, originating from improper validation of lobby data fields related to kicked players. The affected function processes a list of kicked player identifiers using the lobby data key \"kick_num\" to determine the number of entries, and individual kicked player IDs supplied via keys in the format \"kicked_id_%i\". The function does not validate that \"kick_num\" falls within the expected bounds. The game design limits matches to a maximum of 16 players, and the corresponding buffer for storing kicked player IDs is sized accordingly. If \"kick_num\" exceeds this limit, the function continues writing the provided player IDs past the end of the intended buffer and into adjacent memory regions. These adjacent regions contain Steam callback handler structures responsible for processing lobby data updates, lobby messages, and other related events. By supplying an oversized \"kick_num\" value and appropriate \"kicked_id_%i\" fields, an attacker can overwrite fields within the callback handler structures, including function pointers and callback argument values. Successful exploitation may enable control-flow hijacking, potentially allowing arbitrary code execution within the game process."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "description": "CWE-122: Heap-based Buffer Overflow",
              "lang": "en"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-24T15:02:51.022Z",
        "orgId": "37e5125f-f79b-445b-8fad-9564f167944b",
        "shortName": "certcc"
      },
      "references": [
        {
          "url": "https://cwe.mitre.org/data/definitions/122.html"
        },
        {
          "url": "https://kb.cert.org/vuls/id/728712"
        }
      ],
      "source": {
        "discovery": "UNKNOWN"
      },
      "title": "Konami\u0027s Metal Gear Online 3 contains a heap-based buffer overflow",
      "x_generator": {
        "engine": "VINCE 3.0.44",
        "env": "prod",
        "origin": "https://cveawg.mitre.org/api/cve/CVE-2026-19874"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "37e5125f-f79b-445b-8fad-9564f167944b",
    "assignerShortName": "certcc",
    "cveId": "CVE-2026-19874",
    "datePublished": "2026-08-24T15:02:51.022Z",
    "dateReserved": "2026-08-14T14:01:29.531Z",
    "dateUpdated": "2026-08-24T20:04:13.828Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-19874",
      "date": "2026-10-13",
      "epss": "0.00923",
      "percentile": "0.59354"
    },
    "nvd": {
      "cve": {
        "affected": [
          {
            "affectedData": [
              {
                "product": "Metal Gear Online 3",
                "vendor": "Konami",
                "versions": [
                  {
                    "status": "affected",
                    "version": "1.1.2.8"
                  }
                ]
              }
            ],
            "source": "cret@cert.org"
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "A heap-based buffer overflow vulnerability exists in Konami\u0027s Metal Gear Online 3, originating from improper validation of lobby data fields related to kicked players. The affected function processes a list of kicked player identifiers using the lobby data key \"kick_num\" to determine the number of entries, and individual kicked player IDs supplied via keys in the format \"kicked_id_%i\". The function does not validate that \"kick_num\" falls within the expected bounds. The game design limits matches to a maximum of 16 players, and the corresponding buffer for storing kicked player IDs is sized accordingly. If \"kick_num\" exceeds this limit, the function continues writing the provided player IDs past the end of the intended buffer and into adjacent memory regions. These adjacent regions contain Steam callback handler structures responsible for processing lobby data updates, lobby messages, and other related events. By supplying an oversized \"kick_num\" value and appropriate \"kicked_id_%i\" fields, an attacker can overwrite fields within the callback handler structures, including function pointers and callback argument values. Successful exploitation may enable control-flow hijacking, potentially allowing arbitrary code execution within the game process."
          },
          {
            "lang": "es",
            "value": "Una vulnerabilidad de desbordamiento de b\u00fafer basado en mont\u00edculo existe en Metal Gear Online 3 de Konami, originada por una validaci\u00f3n incorrecta de los campos de datos del lobby relacionados con los jugadores expulsados. La funci\u00f3n afectada procesa una lista de identificadores de jugadores expulsados utilizando la clave de datos del lobby \u0027kick_num\u0027 para determinar el n\u00famero de entradas, y los ID de jugadores expulsados individuales proporcionados a trav\u00e9s de claves en el formato \u0027kicked_id_%i\u0027. La funci\u00f3n no valida que \u0027kick_num\u0027 se encuentre dentro de los l\u00edmites esperados. El dise\u00f1o del juego limita las partidas a un m\u00e1ximo de 16 jugadores, y el b\u00fafer correspondiente para almacenar los ID de los jugadores expulsados tiene un tama\u00f1o acorde. Si \u0027kick_num\u0027 excede este l\u00edmite, la funci\u00f3n contin\u00faa escribiendo los ID de jugadores proporcionados m\u00e1s all\u00e1 del final del b\u00fafer previsto y en regiones de memoria adyacentes. Estas regiones adyacentes contienen estructuras de gestor de retrollamada de Steam responsables de procesar las actualizaciones de datos del lobby, los mensajes del lobby y otros eventos relacionados. Al proporcionar un valor de \u0027kick_num\u0027 sobredimensionado y campos \u0027kicked_id_%i\u0027 apropiados, un atacante puede sobrescribir campos dentro de las estructuras del gestor de retrollamada, incluyendo punteros de funci\u00f3n y valores de argumentos de retrollamada. La explotaci\u00f3n exitosa puede permitir el secuestro del flujo de control, permitiendo potencialmente la ejecuci\u00f3n de c\u00f3digo arbitrario dentro del proceso del juego."
          }
        ],
        "id": "CVE-2026-19874",
        "lastModified": "2026-10-12T15:10:00.207",
        "metrics": {
          "cvssMetricV31": [
            {
              "cvssData": {
                "attackComplexity": "LOW",
                "attackVector": "NETWORK",
                "availabilityImpact": "HIGH",
                "baseScore": 9.1,
                "baseSeverity": "CRITICAL",
                "confidentialityImpact": "NONE",
                "integrityImpact": "HIGH",
                "privilegesRequired": "NONE",
                "scope": "UNCHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H",
                "version": "3.1"
              },
              "exploitabilityScore": 3.9,
              "impactScore": 5.2,
              "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "type": "Secondary"
            }
          ],
          "ssvcV203": [
            {
              "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "ssvcData": {
                "id": "CVE-2026-19874",
                "options": [
                  {
                    "exploitation": "none"
                  },
                  {
                    "automatable": "no"
                  },
                  {
                    "technicalImpact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-08-24T20:03:35.495374Z",
                "version": "2.0.3"
              }
            }
          ]
        },
        "published": "2026-08-24T15:16:37.577",
        "references": [
          {
            "source": "cret@cert.org",
            "url": "https://cwe.mitre.org/data/definitions/122.html"
          },
          {
            "source": "cret@cert.org",
            "url": "https://kb.cert.org/vuls/id/728712"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "url": "https://www.kb.cert.org/vuls/id/728712"
          }
        ],
        "sourceIdentifier": "cret@cert.org",
        "vulnStatus": "Deferred",
        "weaknesses": [
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-122"
              }
            ],
            "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
            "type": "Secondary"
          }
        ]
      }
    },
    "vulnrichment": {
      "containers": {
        "adp": [
          {
            "providerMetadata": {
              "dateUpdated": "2026-08-24T16:11:06.391Z",
              "orgId": "af854a3a-2127-422b-91ae-364da2661108",
              "shortName": "CVE"
            },
            "references": [
              {
                "url": "https://www.kb.cert.org/vuls/id/728712"
              }
            ],
            "title": "CVE Program Container"
          },
          {
            "metrics": [
              {
                "cvssV3_1": {
                  "attackComplexity": "LOW",
                  "attackVector": "NETWORK",
                  "availabilityImpact": "HIGH",
                  "baseScore": 9.1,
                  "baseSeverity": "CRITICAL",
                  "confidentialityImpact": "NONE",
                  "integrityImpact": "HIGH",
                  "privilegesRequired": "NONE",
                  "scope": "UNCHANGED",
                  "userInteraction": "NONE",
                  "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H",
                  "version": "3.1"
                }
              },
              {
                "other": {
                  "content": {
                    "id": "CVE-2026-19874",
                    "options": [
                      {
                        "Exploitation": "none"
                      },
                      {
                        "Automatable": "no"
                      },
                      {
                        "Technical Impact": "partial"
                      }
                    ],
                    "role": "CISA Coordinator",
                    "timestamp": "2026-08-24T20:03:35.495374Z",
                    "version": "2.0.3"
                  },
                  "type": "ssvc"
                }
              }
            ],
            "problemTypes": [
              {
                "descriptions": [
                  {
                    "cweId": "CWE-122",
                    "description": "CWE-122 Heap-based Buffer Overflow",
                    "lang": "en",
                    "type": "CWE"
                  }
                ]
              }
            ],
            "providerMetadata": {
              "dateUpdated": "2026-08-24T20:04:07.289Z",
              "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "shortName": "CISA-ADP"
            },
            "title": "CISA ADP Vulnrichment"
          }
        ],
        "cna": {
          "affected": [
            {
              "product": "Metal Gear Online 3",
              "vendor": "Konami",
              "versions": [
                {
                  "status": "affected",
                  "version": "1.1.2.8"
                }
              ]
            }
          ],
          "descriptions": [
            {
              "lang": "en",
              "value": "A heap-based buffer overflow vulnerability exists in Konami\u0027s Metal Gear Online 3, originating from improper validation of lobby data fields related to kicked players. The affected function processes a list of kicked player identifiers using the lobby data key \"kick_num\" to determine the number of entries, and individual kicked player IDs supplied via keys in the format \"kicked_id_%i\". The function does not validate that \"kick_num\" falls within the expected bounds. The game design limits matches to a maximum of 16 players, and the corresponding buffer for storing kicked player IDs is sized accordingly. If \"kick_num\" exceeds this limit, the function continues writing the provided player IDs past the end of the intended buffer and into adjacent memory regions. These adjacent regions contain Steam callback handler structures responsible for processing lobby data updates, lobby messages, and other related events. By supplying an oversized \"kick_num\" value and appropriate \"kicked_id_%i\" fields, an attacker can overwrite fields within the callback handler structures, including function pointers and callback argument values. Successful exploitation may enable control-flow hijacking, potentially allowing arbitrary code execution within the game process."
            }
          ],
          "problemTypes": [
            {
              "descriptions": [
                {
                  "description": "CWE-122: Heap-based Buffer Overflow",
                  "lang": "en"
                }
              ]
            }
          ],
          "providerMetadata": {
            "dateUpdated": "2026-08-24T15:02:51.022Z",
            "orgId": "37e5125f-f79b-445b-8fad-9564f167944b",
            "shortName": "certcc"
          },
          "references": [
            {
              "url": "https://cwe.mitre.org/data/definitions/122.html"
            },
            {
              "url": "https://kb.cert.org/vuls/id/728712"
            }
          ],
          "source": {
            "discovery": "UNKNOWN"
          },
          "title": "Konami\u0027s Metal Gear Online 3 contains a heap-based buffer overflow",
          "x_generator": {
            "engine": "VINCE 3.0.44",
            "env": "prod",
            "origin": "https://cveawg.mitre.org/api/cve/CVE-2026-19874"
          }
        }
      },
      "cveMetadata": {
        "assignerOrgId": "37e5125f-f79b-445b-8fad-9564f167944b",
        "assignerShortName": "certcc",
        "cveId": "CVE-2026-19874",
        "datePublished": "2026-08-24T15:02:51.022Z",
        "dateReserved": "2026-08-14T14:01:29.531Z",
        "dateUpdated": "2026-08-24T20:04:13.828Z",
        "state": "PUBLISHED"
      },
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Drag nodes to arrange them. Double-click a related vulnerability to open it, or a source to visit its link. The Physics button on the left tunes the layout and the simulation; the legend at the bottom left hides or shows nodes by kind and by sighting type.

Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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

JSON

Loading timeline…




    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.