HeyForm is an open-source form builder. Prior to version 3.0.0-rc.9, POST /api/upload has no authentication guard, no global guard, no form-context validation, no openToken requirement, and no session cookie check. Any anonymous internet user can upload files (PDF, DOC/DOCX, XLS/XLSX, CSV, TXT, MP4, images, etc., up to 10 MB) and receive a permanent public URL on the HeyForm domain. The endpoint is used by both authenticated form creators and unauthenticated form submitters; because no form-context binding exists, every request to it is anonymously accepted. Version 3.0.0-rc.9 contains a patch for the issue.
CVE-2026-63429
This high-severity CVE scores 8.6 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3%, top 78% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
- High severity, but no confirmed exploitation yet
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 8.6
- EG Score
- 8.6(medium)
- EG Risk
- 70(Attend)EG Risk 70/100SSVC: Attend
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity86% × 45%Exploitation40% × 40%Automatability100% × 15%Action: Remediate soon — notable exploitation risk. - EPSS PROB
- 0%
- EPSS %ILE
- 22%
- KEV
- Not listed
Published
July 20, 2026
Last Modified
July 22, 2026
Advisory Details (2)
Auto-updated Jul 20, 2026Unauthenticated /api/upload endpoint accepts arbitrary files with no auth/session/form context · Advisory · heyform/heyform · GitHub
https://github.com/heyform/heyform/security/advisories/GHSA-432x-54v2-p7p7commit 092e255e9e02 (heyform/heyform)
Patch available: heyform/heyform v3.0.0-rc.9 (contains commit 092e255e9e02)
https://github.com/heyform/heyform/commit/092e255e9e02565de1b3c057f3dad849160952d2Weakness Classification(2)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 18× in last 7d / 25× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-07-28 20:53 UTCEG score recompute
- 2026-07-28 15:37 UTCEPSS rescore
- 2026-07-27 21:42 UTCEG score recompute
- 2026-07-27 14:14 UTCEPSS rescore
- 2026-07-26 22:22 UTCEG score recompute
- 2026-07-26 14:54 UTCEPSS rescore
- 2026-07-26 14:54 UTCEPSS rescore
- 2026-07-26 10:47 UTCEG score recompute
- 2026-07-25 14:18 UTCEPSS rescore
- 2026-07-25 14:18 UTCEPSS rescore
- 2026-07-24 14:18 UTCEPSS rescore
- 2026-07-24 14:18 UTCEPSS rescore
- 2026-07-23 14:18 UTCEPSS rescore
- 2026-07-23 14:18 UTCEPSS rescore
- 2026-07-23 03:22 UTCEG score recompute
- 2026-07-22 23:37 UTCEG score recompute
- 2026-07-22 14:08 UTCEPSS rescore
- 2026-07-22 14:08 UTCEPSS rescore
- 2026-07-21 15:25 UTCEPSS rescore
- 2026-07-21 15:25 UTCEPSS rescore
- 2026-07-20 18:54 UTCEG score recompute
- 2026-07-20 17:58 UTCEG score recompute
- 2026-07-20 16:37 UTCEG score recompute
- 2026-07-20 16:03 UTCEG score recompute
- 2026-07-20 16:02 UTCMITRE cvelistV5first tracked
Related CVEs(same CWE)
Same CWE
10 shownCWE-434 · CWE-306
- CVE-2009-20011EG 10.0CRITICAL
- CVE-2011-10013EG 10.0CRITICAL
- CVE-2012-10044EG 10.0CRITICAL
- CVE-2013-10066EG 10.0CRITICAL
- CVE-2012-10026EG 10.0CRITICAL
- CVE-2014-125124EG 10.0CRITICAL
- CVE-2010-5326EG 10.0 KEVEPSS p97CRITICAL
- CVE-2007-0956EG 10.0EPSS p98HIGH
- CVE-2012-10054EG 9.8CRITICAL
- CVE-2012-10030EG 9.8CRITICAL
Frequently asked(5)
What is CVE-2026-63429?
When was CVE-2026-63429 disclosed?
Is CVE-2026-63429 actively exploited?
What is the CVSS score of CVE-2026-63429?
How do I remediate CVE-2026-63429?
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-63429
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