Lychee has SSRF bypass via DNS rebinding — PhotoUrlRule only validates IP addresses, not hostnames resolving to internal IPs

{
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "cveMetadata": {
    "cveId": "CVE-2026-33644",
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "dateUpdated": "2026-03-26T20:04:18.728Z",
    "dateReserved": "2026-03-23T15:23:42.216Z",
    "datePublished": "2026-03-26T20:04:18.728Z",
    "state": "PUBLISHED"
  },
  "containers": {
    "cna": {
      "providerMetadata": {
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M",
        "dateUpdated": "2026-03-26T20:04:18.728Z"
      },
      "title": "Lychee has SSRF bypass via DNS rebinding — PhotoUrlRule only validates IP addresses, not hostnames resolving to internal IPs",
      "descriptions": [
        {
          "lang": "en",
          "value": "Lychee is a free, open-source photo-management tool. Prior to version 7.5.2, the SSRF protection in `PhotoUrlRule.php` can be bypassed using DNS rebinding. The IP validation check (line 86-89) only activates when the hostname is an IP address. When a domain name is used, `filter_var($host, FILTER_VALIDATE_IP)` returns `false`, skipping the entire check. Version 7.5.2 patches the issue."
        }
      ],
      "affected": [
        {
          "vendor": "LycheeOrg",
          "product": "Lychee",
          "versions": [
            {
              "version": "< 7.5.2",
              "status": "affected"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "lang": "en",
              "description": "CWE-918: Server-Side Request Forgery (SSRF)",
              "cweId": "CWE-918",
              "type": "CWE"
            }
          ]
        }
      ],
      "references": [
        {
          "url": "https://github.com/LycheeOrg/Lychee/security/advisories/GHSA-5245-4p8c-jwff",
          "name": "https://github.com/LycheeOrg/Lychee/security/advisories/GHSA-5245-4p8c-jwff",
          "tags": [
            "x_refsource_CONFIRM"
          ]
        },
        {
          "url": "https://github.com/LycheeOrg/Lychee/commit/28c5261fb9deab4f9420c8cc2f73a87425939107",
          "name": "https://github.com/LycheeOrg/Lychee/commit/28c5261fb9deab4f9420c8cc2f73a87425939107",
          "tags": [
            "x_refsource_MISC"
          ]
        }
      ],
      "metrics": [
        {}
      ]
    }
  }
}