CVE-2026-63428Disclosure

LOWCVSS 5.8 · MEDIUM

Signal is active with 1 mentions in latest observed window

Immediate actions

  • Track advisory updates for patch or workaround availability

Recommended action window: Monitor and triage in normal cycle

NVD description

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.

0.0/ 10 priority

Sources & remediation

Weakness type (CWE)
CWE-20CWE-915

Priority

LOW

Exploitation

NONE

PoC

NONE

Patch

NONE

Momentum

NONE

Threat summary

  • 1 mentions across 1 observed day

What's happening

  • Technical details provided in 1 signal
  • Disclosure: 1 classified signal
  • 1 total mentions across 1 day

Deep dive

Activity timeline1 mentions / 1d
00111Mentions · 2026-07-20: 1Technical Details · 2026-07-20: 107-20
Signal classification1 categories
Disclosure
1100.0%
Referenced assets1 URL
By indicator
Full discourse1 post
  • CVE@CVEnew
    Disclosure

    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 s… https://www.cve.org/CVERecord?id=CVE-2026-63428

    Post summary

    The tweet announces a vulnerability (CVE‑2026‑63428) in HeyForm related to the handling of `hiddenFields` in the `completeSubmission` method, providing a concise technical detail but no PoC, exploit code, active exploitation evidence, or patch information.

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    57.8K followersView on X

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