Zammad has a Server-side request forgery (SSRF) via webhooks

{
  "id": "5703cb05c0cf65da4a1e9db331cd010d21cdf8a66179dc20710e173f894eaa39",
  "url": "https://osv.dev/vulnerability/CVE-2026-34719",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Zammad has a Server-side request forgery (SSRF) via webhooks",
    "summary": "Zammad is a web based open source helpdesk/customer support system. Prior to 7.0.1 and 6.5.4, the webhook model was missing a proper validation for loop back addresses, or link-local addresses — only the URL scheme (HTTP/HTTPS) as well as the hostname was checked. This could end up in retrieving confidential metadata of cloud/hosting providers. The existing check is now extended and is applied when configuring webhooks as well as triggering webhook jobs. This vulnerability is fixed in 7.0.1 and 6.5.4.",
    "evidence": "osv:CVE-2026-34719",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-34719",
      "aliases": [
        "CVE-2026-34719",
        "GHSA-2vgc-vfh2-rw75"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:L/VI:N/VA:H/SC:L/SI:N/SA:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/zammad/zammad",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "15c7e6d4ffd95c84535d334b7c0ce0bc2fbc5228"
                },
                {
                  "introduced": "f3228274c4feefac470d7efad12f240debd678bc"
                },
                {
                  "last_affected": "f3228274c4feefac470d7efad12f240debd678bc"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:zammad:zammad:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "6.5.4"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "cpe": "cpe:2.3:a:zammad:zammad:7.0.0:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "7.0.0"
                      },
                      {
                        "last_affected": "7.0.0"
                      }
                    ],
                    "source": "CPE_STRING"
                  }
                ]
              }
            }
          ],
          "versions": [
            "7.0.0",
            "6.5.3",
            "6.5.2",
            "6.5.1",
            "6.5.0",
            "6.5.0-alpha",
            "6.4.0-alpha",
            "6.3.0-alpha",
            "6.2.0-alpha",
            "6.1.0-alpha",
            "6.0.0-alpha",
            "5.5.0-alpha",
            "5.4.0-alpha",
            "5.3.0-alpha",
            "5.2.0-alpha",
            "3.7.0",
            "1.6.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-34719.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:23.739082084Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/34xxx/CVE-2026-34719.json",
        "https://github.com/zammad/zammad/security/advisories/GHSA-2vgc-vfh2-rw75",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-34719"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-918"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/34xxx/CVE-2026-34719.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-34719",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 490007,
  "published_at": "2026-04-08T18:02:16.224+00:00"
}