OpenEMR's Missing Authorization in show-signature.php Allows Portal Patients to Read Staff Signatures

{
  "id": "4560fd704639f383ea38a9ff10c0425b46f60f304d47136afa1cc747bca9fe50",
  "url": "https://osv.dev/vulnerability/CVE-2026-33934",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "OpenEMR's Missing Authorization in show-signature.php Allows Portal Patients to Read Staff Signatures",
    "summary": "OpenEMR is a free and open source electronic health records and medical practice management application. Versions prior to 8.0.0.3 have a missing authorization check in `portal/sign/lib/show-signature.php` that allows any authenticated patient portal user to retrieve the drawn signature image of any staff member by supplying an arbitrary `user` value in the POST body. The companion write endpoint (`save-signature.php`) was already hardened against this same issue, but the read endpoint was not updated to match. Version 8.0.0.3 patches the issue.",
    "evidence": "osv:CVE-2026-33934",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2026-33934",
      "aliases": [
        "CVE-2026-33934",
        "GHSA-w9w5-7x6h-657q"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/openemr/openemr",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "7c96c8eefe460d6fadbccbe93d0fa6bf819acd69"
                },
                {
                  "fixed": "ae7ee1872d2e6300b165e24687cc90cf6847a4e5"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:open-emr:openemr:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "8.0.0.3"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "range": [
                      {
                        "fixed": "ae7ee1872d2e6300b165e24687cc90cf6847a4e5"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "range": [
                      {
                        "fixed": "7c96c8eefe460d6fadbccbe93d0fa6bf819acd69"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "v8_0_0_3"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v8_0_0_2",
            "v8_0_0_1",
            "v8_0_0",
            "v3_0_1",
            "v3_0_0",
            "v2_9_0",
            "v2_8_3",
            "v2_8_2",
            "v2_8_1",
            "v2_8_0",
            "v2_7_3-rc1",
            "v2_7_2",
            "v2_7_2-rc2",
            "v2_7_2-rc1"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-33934.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:47.260367757Z",
      "provider": "osv",
      "references": [
        "https://github.com/openemr/openemr/releases/tag/v8_0_0_3",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33934.json",
        "https://github.com/openemr/openemr/security/advisories/GHSA-w9w5-7x6h-657q",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-33934",
        "https://github.com/openemr/openemr/commit/ae7ee1872d2e6300b165e24687cc90cf6847a4e5"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-639",
          "CWE-862"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33934.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-33934",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 515064,
  "published_at": "2026-03-25T23:41:51.601+00:00"
}