{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "cpe": "cpe:2.3:a:f5:nginx_open_source:*:*:*:*:*:*:*:*",
            "extracted_events": [
              {
                "introduced": "0.6.27"
              },
              {
                "last_affected": "0.9.7"
              },
              {
                "introduced": "1.0.0"
              },
              {
                "fixed": "1.28.3"
              },
              {
                "introduced": "1.29.0"
              },
              {
                "fixed": "1.29.7"
              }
            ],
            "source": "CPE_RANGE"
          },
          "events": [
            {
              "introduced": "44186f69a3c7792cd9f62018f4e1429614a121ef"
            },
            {
              "last_affected": "955370fc8c12b1a945941f844adc9df49a0f3f32"
            },
            {
              "introduced": "a2a09a84eb0a7059880500e70b40796ab1dd0c4d"
            },
            {
              "fixed": "9b958b000776c88036cd800c66e7e4ad39e6fd41"
            },
            {
              "introduced": "235f409907fd60eb2d8f6ecdc0e5cb163dd6d45f"
            },
            {
              "fixed": "5ac6f49371f9fcdf21ca4b4fd2a8657576f0885b"
            }
          ],
          "repo": "https://github.com/nginx/nginx",
          "type": "GIT"
        }
      ]
    }
  ],
  "database_specific": {
    "unresolved_ranges": [
      {
        "cpes": [
          "cpe:2.3:a:f5:nginx_plus:r32:p1:*:*:*:*:*:*",
          "cpe:2.3:a:f5:nginx_plus:r32:p2:*:*:*:*:*:*",
          "cpe:2.3:a:f5:nginx_plus:r32:p3:*:*:*:*:*:*",
          "cpe:2.3:a:f5:nginx_plus:r32:p4:*:*:*:*:*:*",
          "cpe:2.3:a:f5:nginx_plus:r33:*:*:*:*:*:*:*",
          "cpe:2.3:a:f5:nginx_plus:r33:p1:*:*:*:*:*:*",
          "cpe:2.3:a:f5:nginx_plus:r33:p2:*:*:*:*:*:*",
          "cpe:2.3:a:f5:nginx_plus:r33:p3:*:*:*:*:*:*",
          "cpe:2.3:a:f5:nginx_plus:r34:*:*:*:*:*:*:*",
          "cpe:2.3:a:f5:nginx_plus:r34:p1:*:*:*:*:*:*",
          "cpe:2.3:a:f5:nginx_plus:r34:p2:*:*:*:*:*:*",
          "cpe:2.3:a:f5:nginx_plus:r35:*:*:*:*:*:*:*",
          "cpe:2.3:a:f5:nginx_plus:r35:p1:*:*:*:*:*:*",
          "cpe:2.3:a:f5:nginx_plus:r36:*:*:*:*:*:*:*",
          "cpe:2.3:a:f5:nginx_plus:r36:p1:*:*:*:*:*:*",
          "cpe:2.3:a:f5:nginx_plus:r36:p2:*:*:*:*:*:*"
        ],
        "extracted_events": [
          {
            "introduced": "r32-p1"
          },
          {
            "last_affected": "r32-p1"
          },
          {
            "introduced": "r32-p2"
          },
          {
            "last_affected": "r32-p2"
          },
          {
            "introduced": "r32-p3"
          },
          {
            "last_affected": "r32-p3"
          },
          {
            "introduced": "r32-p4"
          },
          {
            "last_affected": "r32-p4"
          },
          {
            "introduced": "r33"
          },
          {
            "last_affected": "r33"
          },
          {
            "introduced": "r33-p1"
          },
          {
            "last_affected": "r33-p1"
          },
          {
            "introduced": "r33-p2"
          },
          {
            "last_affected": "r33-p2"
          },
          {
            "introduced": "r33-p3"
          },
          {
            "last_affected": "r33-p3"
          },
          {
            "introduced": "r34"
          },
          {
            "last_affected": "r34"
          },
          {
            "introduced": "r34-p1"
          },
          {
            "last_affected": "r34-p1"
          },
          {
            "introduced": "r34-p2"
          },
          {
            "last_affected": "r34-p2"
          },
          {
            "introduced": "r35"
          },
          {
            "last_affected": "r35"
          },
          {
            "introduced": "r35-p1"
          },
          {
            "last_affected": "r35-p1"
          },
          {
            "introduced": "r36"
          },
          {
            "last_affected": "r36"
          },
          {
            "introduced": "r36-p1"
          },
          {
            "last_affected": "r36-p1"
          },
          {
            "introduced": "r36-p2"
          },
          {
            "last_affected": "r36-p2"
          }
        ],
        "source": "CPE_STRING",
        "vendor_product": "f5:nginx_plus"
      }
    ]
  },
  "details": "NGINX Plus and NGINX Open Source have a vulnerability in the ngx_mail_smtp_module module due to the improper handling of CRLF sequences in DNS responses. This allows an attacker-controlled DNS server to inject arbitrary headers into SMTP upstream requests, leading to potential request manipulation. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.",
  "id": "CVE-2026-28753",
  "modified": "2026-07-08T05:36:59.241304015Z",
  "published": "2026-03-24T15:16:33.560Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://my.f5.com/manage/s/article/K000160367"
    }
  ],
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
      "type": "CVSS_V4"
    }
  ]
}