CVE-2026-63429

HIGHPre-NVD 8.68.6—
EchelonGraph scoreMEDIUM confidence

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).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
Elevated
8.6EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 8.6Exploit: Elevated riskExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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.

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 computed
Severity86% × 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, 2026
🔬 Proof of concept available. Patch available. Sources: github_commit, github.
github Patch Available🟡 PoC Available

Unauthenticated /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-p7p7
github_commit Patch Available

commit 092e255e9e02 (heyform/heyform)

Patch available: heyform/heyform v3.0.0-rc.9 (contains commit 092e255e9e02)

https://github.com/heyform/heyform/commit/092e255e9e02565de1b3c057f3dad849160952d2

Weakness 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.

  1. 2026-07-28 20:53 UTCEG score recompute
  2. 2026-07-28 15:37 UTCEPSS rescore
  3. 2026-07-27 21:42 UTCEG score recompute
  4. 2026-07-27 14:14 UTCEPSS rescore
  5. 2026-07-26 22:22 UTCEG score recompute
  6. 2026-07-26 14:54 UTCEPSS rescore
  7. 2026-07-26 14:54 UTCEPSS rescore
  8. 2026-07-26 10:47 UTCEG score recompute
  9. 2026-07-25 14:18 UTCEPSS rescore
  10. 2026-07-25 14:18 UTCEPSS rescore
  11. 2026-07-24 14:18 UTCEPSS rescore
  12. 2026-07-24 14:18 UTCEPSS rescore
  13. 2026-07-23 14:18 UTCEPSS rescore
  14. 2026-07-23 14:18 UTCEPSS rescore
  15. 2026-07-23 03:22 UTCEG score recompute
  16. 2026-07-22 23:37 UTCEG score recompute
  17. 2026-07-22 14:08 UTCEPSS rescore
  18. 2026-07-22 14:08 UTCEPSS rescore
  19. 2026-07-21 15:25 UTCEPSS rescore
  20. 2026-07-21 15:25 UTCEPSS rescore
  21. 2026-07-20 18:54 UTCEG score recompute
  22. 2026-07-20 17:58 UTCEG score recompute
  23. 2026-07-20 16:37 UTCEG score recompute
  24. 2026-07-20 16:03 UTCEG score recompute
  25. 2026-07-20 16:02 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-63429?
CVE-2026-63429 is a high vulnerability published on July 20, 2026. 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,…
When was CVE-2026-63429 disclosed?
CVE-2026-63429 was first published in the National Vulnerability Database on July 20, 2026, with the most recent update on July 22, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-63429 actively exploited?
CVE-2026-63429 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 77.9% of all scored CVEs.
What is the CVSS score of CVE-2026-63429?
CVE-2026-63429 has a CVSS v3 base score of 8.6 (NVD).
How do I remediate CVE-2026-63429?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-63429, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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