HeyForm Vulnerable to Stored XSS via Unauthenticated SVG File Upload

{
  "id": "74aaebbca873c0ed9f777600f865cf4e34d92f30ef8fb41edaab816358d4c446",
  "url": "https://osv.dev/vulnerability/CVE-2026-45797",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "HeyForm Vulnerable to Stored XSS via Unauthenticated SVG File Upload",
    "summary": "HeyForm is an open-source form builder. Prior to version 3.0.0-rc.7, the `/api/upload` endpoint allows unauthenticated file uploads including SVG files. Uploaded SVGs are stored in the static assets directory and served with `Content-Type: image/svg+xml` by Express's serve-static middleware, allowing an attacker to achieve stored cross-site scripting (XSS) on the heyform domain without any authentication. Version 3.0.0-rc.7 contains a patch for the issue.",
    "evidence": "osv:CVE-2026-45797",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2026-45797",
      "aliases": [
        "CVE-2026-45797",
        "GHSA-m94h-jxvc-hhch"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/heyform/heyform",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "c8660e4fe4b910e8de2c6ca6e9840a9a67597d5a"
                },
                {
                  "fixed": "144240e5545d10fd9e120d05ccb402a6d7064674"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "3.0.0-rc.7"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "range": [
                      {
                        "fixed": "144240e5545d10fd9e120d05ccb402a6d7064674"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v3.0.0-rc.6",
            "v3.0.0-rc.5",
            "v3.0.0-rc.4",
            "v3.0.0-rc.3",
            "v3.0.0-rc.2",
            "v3.0.0-rc.1",
            "v3.0.0-alpha.3",
            "v3.0.0-alpha-2",
            "v0.1.0",
            "v0.0.17",
            "v0.0.16",
            "v0.0.15",
            "v0.0.13",
            "v0.0.12",
            "v0.0.11",
            "v0.0.10",
            "v0.0.9",
            "v0.0.8",
            "v0.0.7",
            "v0.0.6",
            "v0.0.5",
            "v0.0.4",
            "v0.0.3",
            "v0.0.2",
            "v0.0.1"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-45797.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:20.543737039Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/45xxx/CVE-2026-45797.json",
        "https://github.com/heyform/heyform/security/advisories/GHSA-m94h-jxvc-hhch",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-45797",
        "https://github.com/heyform/heyform/commit/144240e5545d10fd9e120d05ccb402a6d7064674"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-434",
          "CWE-79"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/45xxx/CVE-2026-45797.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-45797",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 486586,
  "published_at": "2026-07-20T15:43:13.473+00:00"
}