Vulnerability in HeyForm (CVE-2026-63428)
Summary
Vulnerability in HeyForm (CVE-2026-63428). Risk of unauthorized operations or information disclosure. Exploitable via completeSubmission.
Original description
The description as published by the source.
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: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-63428 has been found in HeyForm.
Attackers can target a specific entry point like completeSubmission over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 5.8/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "HeyForm CVE-2026-63428" on the vendor's site.
CVE-2026-63428 (HeyForm) — CWE-20 / CVSS v3 5.8
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: completeSubmission / submission.hiddenFields / name / form.hiddenFields
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-20) exists in HeyForm. Attackers reach the vulnerable code path via completeSubmission without authentication.
Check the vendor advisory for the affected versions of HeyForm. Attack surface: completeSubmission / submission.hiddenFields / name / form.hiddenFields.
Severity: Medium (CVSS 5.8/10). Risk of unauthorized operations or information disclosure.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'HeyForm' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'HeyForm' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
HeyFormを grep し、稼働しているサービス・バージョンを把握する。 -
2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
References
- advisory github.com
- advisory github.com
- advisory nvd.nist.gov
- patch github.com