CVE-2026-100304

TDuck survey form 6.0 contains an information disclosure vulnerability in FormAuthUtils.hasPermission that fails open when a form does not exist, allowing authenticated users to access deleted form submissions. Attackers can read orphaned submission data including personal information by providing a known dataId to the GET /user/form/data/details endpoint after the form has been permanently deleted.

• https://github.com/LinYuanyi1/cve-request-poc/blob/adffc39b78cad18cd489cbf7454853bf0f744b7f/tduck/poc_form_data_details_orphan.py
• https://github.com/TDuckCloud/tduck-survey-form
• https://github.com/TDuckCloud/tduck-survey-form/blob/43ffa9c993e38936fc4de7d8e5aee82bbaa19502/tduck-api/src/main/java/com/tduck/cloud/api/web/controller/UserFormController.java#L451-L459
• https://github.com/TDuckCloud/tduck-survey-form/blob/43ffa9c993e38936fc4de7d8e5aee82bbaa19502/tduck-form/src/main/java/com/tduck/cloud/form/service/impl/UserFormDataServiceImpl.java#L169-L187
• https://github.com/TDuckCloud/tduck-survey-form/blob/43ffa9c993e38936fc4de7d8e5aee82bbaa19502/tduck-form/src/main/java/com/tduck/cloud/form/util/FormAuthUtils.java#L25-L39
• https://www.vulncheck.com/advisories/tduck-survey-form-6.0-information-disclosure-via-fail-open-form-ownership-check