{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "versions": [
              {
                "introduced": "4.5.0-RC1"
              },
              {
                "fixed": "4.16.19"
              }
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1a8db788c8b3de85c3aed09ac34046e230079481"
            }
          ],
          "repo": "https://github.com/craftcms/cms",
          "type": "GIT"
        },
        {
          "database_specific": {
            "versions": [
              {
                "introduced": "5.0.0-RC1"
              },
              {
                "fixed": "5.8.23"
              }
            ]
          },
          "events": [
            {
              "introduced": "04755d93f86d07cc183db47db8a0eee106892e30"
            },
            {
              "fixed": "daf0ed01c7d2c194ba4a405290e43934d020eef2"
            }
          ],
          "repo": "https://github.com/craftcms/cms",
          "type": "GIT"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-918"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/27xxx/CVE-2026-27129.json"
  },
  "details": "Craft is a content management system (CMS). In versions 4.5.0-RC1 through 4.16.18 and 5.0.0-RC1 through 5.8.22, the SSRF validation in Craft CMS’s GraphQL Asset mutation uses `gethostbyname()`, which only resolves IPv4 addresses. When a hostname has only AAAA (IPv6) records, the function returns the hostname string itself, causing the blocklist comparison to always fail and completely bypassing SSRF protection. This is a bypass of the security fix for CVE-2025-68437. Exploitation requires GraphQL schema permissions for editing assets in the `\u003cVolumeName\u003e` volume and creating assets in the `\u003cVolumeName\u003e` volume. These permissions may be granted to authenticated users with appropriate GraphQL schema access and/or Public Schema (if misconfigured with write permissions). Versions 4.16.19 and 5.8.23 patch the issue.",
  "id": "CVE-2026-27129",
  "modified": "2026-04-01T23:10:06.513920843Z",
  "published": "2026-02-24T02:45:45.494Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/27xxx/CVE-2026-27129.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/craftcms/cms/security/advisories/GHSA-v2gc-rm6g-wrw9"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/craftcms/cms/security/advisories/GHSA-x27p-wfqw-hfcc"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-27129"
    },
    {
      "type": "FIX",
      "url": "https://github.com/craftcms/cms/commit/2825388b4f32fb1c9bd709027a1a1fd192d709a3"
    }
  ],
  "related": [
    "GHSA-v2gc-rm6g-wrw9",
    "GHSA-x27p-wfqw-hfcc"
  ],
  "schema_version": "1.7.3",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:P",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Cloud Metadata SSRF Protection Bypass via IPv6 Resolution"
}