OpenSignLabs opensignserver - Missing Authentication for Critical Function

{
  "id": "064f60e6c7fbe87afb678209200fa5cc65f68a92b7dd2c4d0da3b8fc1fd73521",
  "url": "https://osv.dev/vulnerability/CVE-2026-72688",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "OpenSignLabs opensignserver - Missing Authentication for Critical Function",
    "summary": "A missing authentication vulnerability in OpenSignLabs opensignserver through 2.37.0 allows an unauthenticated remote attacker to read arbitrary stored documents via the fileupload Parse cloud function. The function mints MASTER_KEY-signed file access tokens for any caller-supplied URL without performing any session check, defeating the only access control protecting stored contract files.",
    "evidence": "osv:CVE-2026-72688",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-72688",
      "aliases": [
        "CVE-2026-72688"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/opensignlabs/opensign",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "last_affected": "a56b87a7020de74b0f7dda29d7ec3de382a456bb"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "last_affected": "2.37.0"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandardRange"
                  },
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "last_affected": "2.37.0"
                      }
                    ],
                    "source": "DESCRIPTION"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v2.38.0",
            "v2.37.0",
            "v2.36.0",
            "v2.35.0",
            "v2.34.0",
            "v2.33.0",
            "v2.32.0",
            "v2.31.0",
            "v2.30.0",
            "v2.29.2",
            "v2.29.1",
            "v2.29.0",
            "v2.28.0",
            "v2.27.2",
            "v2.26.0",
            "v2.25.0",
            "v2.24.1",
            "v2.23.0",
            "v2.22.0",
            "v2.21.1",
            "v2.21.0",
            "v2.20.1",
            "v2.20.0",
            "v2.19.2",
            "v2.19.1",
            "v2.19.0",
            "v2.18.0",
            "v2.17.0",
            "v2.16.0",
            "v2.15.0",
            "v2.13.0",
            "v2.7.0",
            "v2.12.0",
            "v2.6.0",
            "v2.5.0",
            "v2.4.1",
            "v2.4.0",
            "v2.3.3",
            "v2.3.2",
            "v2.3.1",
            "v2.3.0",
            "v2.2.0",
            "v2.1.2",
            "v2.1.1",
            "v2.1.0",
            "v2.0.0",
            "v1.8.1",
            "v1.8.0",
            "v1.7.3",
            "v1.7.2",
            "v1.7.1",
            "v1.7.0",
            "v1.6.2",
            "v1.6.1",
            "v1.6.0",
            "v1.5.8",
            "v1.5.1",
            "v1.5.0",
            "v1.4.2",
            "v1.4.1",
            "v1.4.0-beta",
            "1.3.2-beta",
            "v1.3.1-beta",
            "v1.3.0-beta",
            "v1.2.2-beta",
            "v1.2.1-beta",
            "v1.2.0-beta",
            "v1.1.1-beta",
            "v1.1.0-beta",
            "v1.0.7-beta",
            "v1.0.6-beta",
            "v1.0.5-beta",
            "v1.0.3"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-72688.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:52.854390426Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/72xxx/CVE-2026-72688.json",
        "https://github.com/OpenSignLabs/OpenSign",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-72688"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-306"
        ],
        "cna_assigner": "TuranSec",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/72xxx/CVE-2026-72688.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-72688",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 521833,
  "published_at": "2026-08-10T11:59:02.77+00:00"
}