FKIE_CVE-2026-19874

Vulnerability from fkie_nvd - Published: 2026-08-24 15:16 - Updated: 2026-08-24 17:17
Severity
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.
References
cret@cert.orghttps://cwe.mitre.org/data/definitions/122.html
cret@cert.orghttps://kb.cert.org/vuls/id/728712
af854a3a-2127-422b-91ae-364da2661108https://www.kb.cert.org/vuls/id/728712
Impacted products
Vendor Product Version
To clipboard 

{
  "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."
    }
  ],
  "id": "CVE-2026-19874",
  "lastModified": "2026-08-24T17:17:22.227",
  "metrics": {},
  "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": "Received"
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





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.


Detection rules are retrieved from Rulezet.