{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "fixed": "7.22"
              }
            ],
            "source": [
              "AFFECTED_FIELD",
              "REFERENCES"
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "a9df523f76f43a38bd53b4232b9cfd4c16869e71"
            },
            {
              "fixed": "beb73a65a99619ff349c59037ea5197f27c7e533"
            }
          ],
          "repo": "https://github.com/cesanta/mongoose",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-jp6g-796f-39vp"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-295"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/73xxx/CVE-2026-73253.json"
  },
  "details": "Mongoose is an embedded web server and network library. Prior to version 7.22, an on-path network attacker with a wildcard certificate for a parent domain can impersonate deeper subdomains to a client using the built-in TLS stack. The mg_tls_verify_cert_san() and mg_tls_verify_cert_cn() functions in src/tls_builtin.c call mg_match(), whose wildcard can cross DNS label boundaries, so a pattern such as *.example.com can match foo.bar.example.com. The resulting hostname verification bypass permits interception and modification of TLS traffic. This issue is fixed in version 7.22.",
  "id": "CVE-2026-73253",
  "modified": "2026-09-11T03:30:59.503940382Z",
  "published": "2026-08-20T17:41:02.495Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/cesanta/mongoose/releases/tag/7.22"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/73xxx/CVE-2026-73253.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/cesanta/mongoose/security/advisories/GHSA-jp6g-796f-39vp"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-73253"
    },
    {
      "type": "FIX",
      "url": "https://github.com/cesanta/mongoose/commit/a9df523f76f43a38bd53b4232b9cfd4c16869e71"
    },
    {
      "type": "FIX",
      "url": "https://github.com/cesanta/mongoose/pull/3611"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Mongoose: TLS Hostname Verification Bypass via Overly Permissive Wildcard Matching"
}