{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "cpe": "cpe:2.3:a:cesanta:mongoose:*:*:*:*:*:*:*:*",
            "extracted_events": [
              {
                "introduced": "7.0"
              },
              {
                "last_affected": "7.0"
              },
              {
                "introduced": "7.1"
              },
              {
                "last_affected": "7.1"
              },
              {
                "introduced": "7.2"
              },
              {
                "last_affected": "7.2"
              },
              {
                "introduced": "7.3"
              },
              {
                "last_affected": "7.3"
              },
              {
                "introduced": "7.4"
              },
              {
                "last_affected": "7.4"
              },
              {
                "introduced": "7.5"
              },
              {
                "last_affected": "7.5"
              },
              {
                "introduced": "7.6"
              },
              {
                "last_affected": "7.6"
              },
              {
                "introduced": "7.7"
              },
              {
                "last_affected": "7.7"
              },
              {
                "introduced": "7.8"
              },
              {
                "last_affected": "7.8"
              },
              {
                "introduced": "7.9"
              },
              {
                "last_affected": "7.9"
              },
              {
                "introduced": "7.10"
              },
              {
                "last_affected": "7.10"
              },
              {
                "introduced": "7.11"
              },
              {
                "last_affected": "7.11"
              },
              {
                "introduced": "7.12"
              },
              {
                "last_affected": "7.12"
              },
              {
                "introduced": "7.13"
              },
              {
                "last_affected": "7.13"
              },
              {
                "introduced": "7.14"
              },
              {
                "last_affected": "7.14"
              },
              {
                "introduced": "7.15"
              },
              {
                "last_affected": "7.15"
              },
              {
                "introduced": "7.16"
              },
              {
                "last_affected": "7.16"
              },
              {
                "introduced": "7.17"
              },
              {
                "last_affected": "7.17"
              },
              {
                "introduced": "7.18"
              },
              {
                "last_affected": "7.18"
              },
              {
                "introduced": "7.19"
              },
              {
                "last_affected": "7.19"
              },
              {
                "introduced": "7.20"
              },
              {
                "last_affected": "7.20"
              },
              {
                "fixed": "7.21"
              }
            ],
            "source": [
              "AFFECTED_FIELD",
              "CPE_RANGE",
              "REFERENCES"
            ]
          },
          "events": [
            {
              "introduced": "54250f5fbfa1972b96ef593b457abd6184ea65a0"
            },
            {
              "fixed": "b1c2ffe1a0aa13e3d94075b1a2c66b8b43ac9116"
            }
          ],
          "repo": "https://github.com/cesanta/mongoose",
          "type": "GIT"
        }
      ],
      "versions": [
        "7.0",
        "7.1",
        "7.10",
        "7.11",
        "7.12",
        "7.13",
        "7.14",
        "7.15",
        "7.16",
        "7.17",
        "7.18",
        "7.19",
        "7.2",
        "7.20",
        "7.3",
        "7.4",
        "7.5",
        "7.6",
        "7.7",
        "7.8",
        "7.9"
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "VulDB",
    "cwe_ids": [
      "CWE-404",
      "CWE-835"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/6xxx/CVE-2026-6985.json"
  },
  "details": "A weakness has been identified in Cesanta Mongoose up to 7.20. This vulnerability affects the function handle_opt of the file /src/net_builtin.c of the component TCP Option Handler. This manipulation of the argument optlen causes infinite loop. The attack is possible to be carried out remotely. The exploit has been made available to the public and could be used for attacks. Upgrading to version 7.21 is able to resolve this issue. Upgrading the affected component is advised. VulDB has contacted the vendor early and they confirmed quickly, that this issue got fixed already.",
  "id": "CVE-2026-6985",
  "modified": "2026-08-07T11:31:07.134372645Z",
  "published": "2026-04-25T16:15:13.639Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/6xxx/CVE-2026-6985.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-6985"
    },
    {
      "type": "ADVISORY",
      "url": "https://vuldb.com/submit/796230"
    },
    {
      "type": "ADVISORY",
      "url": "https://vuldb.com/vuln/359528"
    },
    {
      "type": "REPORT",
      "url": "https://vuldb.com/vuln/359528/cti"
    },
    {
      "type": "FIX",
      "url": "https://github.com/cesanta/mongoose/releases/tag/7.21"
    },
    {
      "type": "EVIDENCE",
      "url": "https://github.com/dwBruijn/CVEs/blob/main/Mongoose/TCP_opt_dos.md"
    }
  ],
  "schema_version": "1.8.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Cesanta Mongoose TCP Option net_builtin.c handle_opt infinite loop"
}