Cross-origin data theft via credentialed origin reflection
Published Aug 28, 2026 · Updated Aug 29, 2026
Improper CORS policy in HeyForm before 3.0.0-rc.8 allows remote attackers to read or modify authenticated GraphQL data. The server's enableCors call in packages/server/src/main.ts sets origin to true and credentials to true, echoing every request Origin while permitting browsers to expose credentialed responses. Exploitation requires a logged-in user to visit an attacker-controlled page; the page can then read workspace and respondent data or issue account and content mutations with the user's cookies.
Summary
What happened
Improper CORS policy in HeyForm before 3.0.0-rc.8 allows remote attackers to read or modify authenticated GraphQL data. The server's enableCors call in packages/server/src/main.ts sets origin to true and credentials to true, echoing every request Origin while permitting browsers to expose credentialed responses. Exploitation requires a logged-in user to visit an attacker-controlled page; the page can then read workspace and respondent data or issue account and content mutations with the user's cookies.
The record
- CVE
- CVE-2026-82291
- Published
- Aug 28, 2026
- Updated
- Aug 29, 2026
- Vendor
- HeyForm
- Product
- HeyForm
- Classifications
- CWE-942, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 28, 2026CVE publishedPublication date reported by the CVE source.
- Aug 29, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <3.0.0-rc.8
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Credentialed GraphQL cross-origin exploit pagefunctional · validated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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