Security advisory

{
  "id": "b77a55a001a970adcdaf43c463220778e2621821e1c8ebb233e5ea09967d97a7",
  "url": "https://osv.dev/vulnerability/CVE-2021-47793",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2021-47793",
    "summary": "Telegram Desktop 2.9.2 contains a denial of service vulnerability that allows attackers to crash the application by sending an oversized message payload. Attackers can generate a 9 million byte buffer and paste it into the messaging interface to trigger an application crash.",
    "evidence": "osv:CVE-2021-47793",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2021-47793",
      "aliases": [
        "CVE-2021-47793"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:L/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"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/telegramdesktop/tdesktop",
              "type": "GIT",
              "events": [
                {
                  "introduced": "437d35d8c4ffa4389e870f700ab61a9742d61642"
                },
                {
                  "last_affected": "437d35d8c4ffa4389e870f700ab61a9742d61642"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:telegram:telegram_desktop:2.9.2:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "2.9.2"
                      },
                      {
                        "last_affected": "2.9.2"
                      }
                    ],
                    "source": "CPE_STRING"
                  }
                ]
              }
            }
          ],
          "versions": [
            "2.9.2",
            "v2.9.2"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-47793.json"
          }
        }
      ],
      "modified": "2026-10-24T10:30:56.540617289Z",
      "provider": "osv",
      "references": [
        "https://telegram.org",
        "https://www.vulncheck.com/advisories/telegram-desktop-denial-of-service-poc",
        "https://www.exploit-db.com/exploits/50247"
      ],
      "provider_metadata": {}
    },
    "related_cves": [
      {
        "value": "CVE-2021-47793",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 438694,
  "published_at": "2026-01-16T00:16:23.207+00:00"
}