Security advisory

{
  "id": "8a2920718ad282ad9f16d568e1dea05f39411a95c7f2d3fa71f97fbd02a0ca0d",
  "url": "https://osv.dev/vulnerability/CVE-2020-25756",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2020-25756",
    "summary": "A buffer overflow vulnerability exists in the mg_get_http_header function in Cesanta Mongoose 6.18 due to a lack of bounds checking. A crafted HTTP header can exploit this bug. NOTE: a committer has stated \"this will not happen in practice.",
    "evidence": "osv:CVE-2020-25756",
    "products": [],
    "severity": "critical",
    "structured": {
      "id": "CVE-2020-25756",
      "aliases": [
        "CVE-2020-25756"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/cesanta/mongoose",
              "type": "GIT",
              "events": [
                {
                  "introduced": "80d74e9e341d541f71c0fa587d22cec89be32dd5"
                },
                {
                  "last_affected": "80d74e9e341d541f71c0fa587d22cec89be32dd5"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:cesanta:mongoose:6.18:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "6.18"
                      },
                      {
                        "last_affected": "6.18"
                      }
                    ],
                    "source": "CPE_STRING"
                  }
                ]
              }
            }
          ],
          "versions": [
            "6.18"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2020-25756.json"
          }
        }
      ],
      "modified": "2026-10-20T10:52:54.136508727Z",
      "provider": "osv",
      "references": [
        "https://github.com/cesanta/mongoose/issues/1135"
      ],
      "provider_metadata": {}
    },
    "related_cves": [
      {
        "value": "CVE-2020-25756",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 384014,
  "published_at": "2020-09-18T05:15:13.197+00:00"
}