Security advisory

{
  "id": "f12fc4277eb80ab9c62dc6b02815de6204318b604a5668fcb35b840c162a510b",
  "url": "https://osv.dev/vulnerability/CVE-2021-26788",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2021-26788",
    "summary": "Oryx Embedded CycloneTCP 1.7.6 to 2.0.0, fixed in 2.0.2, is affected by incorrect input validation, which may cause a denial of service (DoS). To exploit the vulnerability, an attacker needs to have TCP connectivity to the target system. Receiving a maliciously crafted TCP packet from an unauthenticated endpoint is sufficient to trigger the bug.",
    "evidence": "osv:CVE-2021-26788",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2021-26788",
      "aliases": [
        "CVE-2021-26788"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/oryx-embedded/cyclonetcp",
              "type": "GIT",
              "events": [
                {
                  "introduced": "07ad133815eaaac4b6a329faf967fe866b06e2c9"
                },
                {
                  "last_affected": "248b6e2063906d2c98a096d235cb008424d72fa6"
                },
                {
                  "fixed": "de5336016edbe1e90327d0ed1cba5c4e49114366"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:oryx-embedded:cyclonetcp:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "1.7.6"
                      },
                      {
                        "last_affected": "2.0.0"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "range": [
                      {
                        "fixed": "de5336016edbe1e90327d0ed1cba5c4e49114366"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v2.0.0",
            "v1.9.8",
            "v1.9.6",
            "v1.9.4",
            "v1.9.2",
            "v1.9.0",
            "v1.8.6",
            "v1.8.2",
            "v1.8.0",
            "v1.7.8",
            "v1.7.6"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-26788.json"
          }
        }
      ],
      "modified": "2026-10-20T10:54:34.598777874Z",
      "provider": "osv",
      "references": [
        "https://github.com/Oryx-Embedded/CycloneTCP/commit/de5336016edbe1e90327d0ed1cba5c4e49114366?branch=de5336016edbe1e90327d0ed1cba5c4e49114366&diff=split"
      ],
      "provider_metadata": {}
    },
    "related_cves": [
      {
        "value": "CVE-2021-26788",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 385628,
  "published_at": "2021-03-08T13:15:12.737+00:00"
}