{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "fixed": "7.22"
              }
            ],
            "source": [
              "DESCRIPTION",
              "REFERENCES"
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "beb73a65a99619ff349c59037ea5197f27c7e533"
            },
            {
              "fixed": "c288ac1f38424ffdd4d2fd5e1893fd4962642db3"
            }
          ],
          "repo": "https://github.com/cesanta/mongoose",
          "type": "GIT"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "VulnCheck",
    "cwe_ids": [
      "CWE-125"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/11xxx/CVE-2026-11404.json"
  },
  "details": "Cesanta Mongoose before 7.22 contains an out-of-bounds read in the built-in TLS server function mg_tls_server_recv_hello(), which uses an attacker-controlled session_id_len byte from a TLS ClientHello as a buffer index without validating it against the length of received data. A remote, unauthenticated attacker can send a single crafted ClientHello with an oversized session id length to read past the receive buffer, crashing any HTTPS, MQTTS, or WSS service built on MG_TLS_BUILTIN.",
  "id": "CVE-2026-11404",
  "modified": "2026-07-15T01:49:07.155064125Z",
  "published": "2026-07-09T15:13:40.148Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/11xxx/CVE-2026-11404.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/cesanta/mongoose/releases/tag/7.22"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-11404"
    },
    {
      "type": "ADVISORY",
      "url": "https://www.vulncheck.com/advisories/cesanta-mongoose-out-of-bounds-read-in-mg-tls-builtin-clienthello-session-id-parsing"
    },
    {
      "type": "FIX",
      "url": "https://github.com/cesanta/mongoose/commit/c288ac1f38424ffdd4d2fd5e1893fd4962642db3"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/cesanta/mongoose"
    }
  ],
  "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:H/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Cesanta Mongoose before 7.22 Out-of-Bounds Read in MG_TLS_BUILTIN ClientHello Session ID Parsing"
}