{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-63428","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","state":"PUBLISHED","assignerShortName":"GitHub_M","dateReserved":"2026-07-16T19:35:57.766Z","datePublished":"2026-07-20T15:50:14.065Z","dateUpdated":"2026-07-20T16:13:26.732Z"},"containers":{"cna":{"title":"HeyForm: completeSubmission persists submitter-supplied hidden fields verbatim without validating against the form's declared hidden-field set","problemTypes":[{"descriptions":[{"cweId":"CWE-20","lang":"en","description":"CWE-20: Improper Input Validation","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-915","lang":"en","description":"CWE-915: Improperly Controlled Modification of Dynamically-Determined Object Attributes","type":"CWE"}]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":5.8,"baseSeverity":"MEDIUM","confidentialityImpact":"NONE","integrityImpact":"LOW","privilegesRequired":"NONE","scope":"CHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N","version":"3.1"}}],"references":[{"name":"https://github.com/heyform/heyform/security/advisories/GHSA-r7vg-xh87-v4w3","tags":["x_refsource_CONFIRM"],"url":"https://github.com/heyform/heyform/security/advisories/GHSA-r7vg-xh87-v4w3"},{"name":"https://github.com/heyform/heyform/commit/092e255e9e02565de1b3c057f3dad849160952d2","tags":["x_refsource_MISC"],"url":"https://github.com/heyform/heyform/commit/092e255e9e02565de1b3c057f3dad849160952d2"}],"affected":[{"vendor":"heyform","product":"heyform","versions":[{"version":"< 3.0.0-rc.9","status":"affected"}]}],"providerMetadata":{"orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M","dateUpdated":"2026-07-20T15:50:14.065Z"},"descriptions":[{"lang":"en","value":"HeyForm is an open-source form builder. Prior to version 3.0.0-rc.9, `completeSubmission` accepts a `hiddenFields: [{id, name, value}]` array from the submitter and stores it verbatim in `submission.hiddenFields`, without validating the supplied `id`/`name` against the form's declared `form.hiddenFields` schema. An anonymous form submitter can therefore inject arbitrary key/value pairs (including XSS payloads, fake authorization metadata, integration-relevant values) into the stored submission. These fields are subsequently forwarded as-is to every webhook integration registered on the form. Version 3.0.0-rc.9 contains a patch for the issue."}],"source":{"advisory":"GHSA-r7vg-xh87-v4w3","discovery":"UNKNOWN"}},"adp":[{"references":[{"url":"https://github.com/heyform/heyform/security/advisories/GHSA-r7vg-xh87-v4w3","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-07-20T16:11:40.127768Z","id":"CVE-2026-63428","options":[{"Exploitation":"poc"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-07-20T16:13:26.732Z"}}]}}