CVE-2026-63428

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.

CVSS v3 5.8 MEDIUM

5.8^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 3.9 / Impact : 1.4

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact LOW

Availability Impact NONE

Scope CHANGED

References

Link	Resource
https://github.com/heyform/heyform/commit/092e255e9e02565de1b3c057f3dad849160952d2
https://github.com/heyform/heyform/security/advisories/GHSA-r7vg-xh87-v4w3
https://github.com/heyform/heyform/security/advisories/GHSA-r7vg-xh87-v4w3

Configurations

No configuration.

History

20 Jul 2026, 17:18

Type	Values Removed	Values Added
References	~~() https://github.com/heyform/heyform/security/advisories/GHSA-r7vg-xh87-v4w3 -~~	() https://github.com/heyform/heyform/security/advisories/GHSA-r7vg-xh87-v4w3 -

20 Jul 2026, 16:17

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-07-20 16:17

Updated : 2026-07-22 20:50

NVD link : CVE-2026-63428

Mitre link : CVE-2026-63428

CVE.ORG link : CVE-2026-63428

JSON object : View

Products Affected

No product.

CWE

CWE-20

Improper Input Validation

CWE-915

Improperly Controlled Modification of Dynamically-Determined Object Attributes

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