{
  "containers": {
    "cna": {
      "affected": [
        {
          "product": "mongoose",
          "vendor": "cesanta",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 7.23"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Mongoose is an embedded web server and network library. Prior to 7.23, the built-in TCP/IP stack enabled by MG_ENABLE_TCPIP in src/net_builtin.c does not reject a TCP option whose declared opts[1] length exceeds the remaining option bytes. In handle_opt(), a NOP followed by a truncated MSS option causes opts[3] to be read outside the declared options area and used as the low byte of dmss. An unauthenticated remote peer can corrupt the per-connection MSS value so later mg_send() calls transmit truncated or zero-length application payloads while the TCP connection otherwise appears healthy. This issue is fixed in version 7.23."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "NONE",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-20",
              "description": "CWE-20: Improper Input Validation",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-125",
              "description": "CWE-125: Out-of-bounds Read",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-14T18:25:41.102Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/cesanta/mongoose/security/advisories/GHSA-3fmr-92g4-wchx",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/cesanta/mongoose/security/advisories/GHSA-3fmr-92g4-wchx"
        },
        {
          "name": "https://github.com/cesanta/mongoose/commit/cc7c6d2d18c28fcc6d085633dddd88402946140a",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/cesanta/mongoose/commit/cc7c6d2d18c28fcc6d085633dddd88402946140a"
        },
        {
          "name": "https://github.com/cesanta/mongoose/releases/tag/7.23",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/cesanta/mongoose/releases/tag/7.23"
        }
      ],
      "source": {
        "advisory": "GHSA-3fmr-92g4-wchx",
        "discovery": "UNKNOWN"
      },
      "title": "Mongoose: handle_opt() missing opts[1] \u003e len check \u2014 1-byte OOB read corrupts TCP MSS, silences mg_send() per connection"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-73261",
    "datePublished": "2026-10-14T18:25:41.102Z",
    "dateReserved": "2026-08-11T17:18:01.598Z",
    "dateUpdated": "2026-10-14T18:25:41.102Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}