What is CVE-2026-82291?

CVE-2026-82291 is a high-severity vulnerability in Heyform, classified under Permissive Cross-domain Policy with Untrusted Domains. CVSS score: 8.1/10. Published 2026-08-28.

How severe is CVE-2026-82291?

High severity. CVSS v3 base score is 8.1 out of 10.

Vulnerability in Heyform

CVE-2026-82291

HeyForm before 3.0.0-rc.8 reflects the request Origin header in CORS responses while allowing credentials, enabling cross-origin requests with authentication. Attackers can execute authenticated GraphQL queries from malicious pages visited by logged-in users to access workspaces, projects, forms, submissions, and respondent data, or modify account settings.

CVSS v3 metric

CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N.

Affected products

Heyform

Weakness classification (CWE)

CWE-942 — Permissive Cross-domain Policy with Untrusted Domains

References

disclosure@vulncheck.com (vendor-advisory)
disclosure@vulncheck.com (technical-description)
disclosure@vulncheck.com (patch)
disclosure@vulncheck.com (product)
disclosure@vulncheck.com (third-party-advisory)

Frequently asked questions

What is CVE-2026-82291?: CVE-2026-82291 is a high-severity vulnerability in Heyform, classified under Permissive Cross-domain Policy with Untrusted Domains. CVSS score: 8.1/10. Published 2026-08-28.
How severe is CVE-2026-82291?: High severity. CVSS v3 base score is 8.1 out of 10.