Unauthenticated script execution via HTML-served unescaped JSON
Published Apr 7, 2026 · Updated Apr 7, 2026
Reflected XSS in Rocketgenius Gravity Forms 2.9.30 and earlier allows remote attackers to execute scripts via crafted form_ids values. GFCommon::send_json() returns JSON containing unencoded angle brackets inside an HTML-comment-wrapped text/html response, so browsers parse injected tags as markup. A public config_nonce from any page containing a form and interaction by an unauthenticated visitor are required; authenticated visitors are not affected.
Summary
What happened
Reflected XSS in Rocketgenius Gravity Forms 2.9.30 and earlier allows remote attackers to execute scripts via crafted form_ids values. GFCommon::send_json() returns JSON containing unencoded angle brackets inside an HTML-comment-wrapped text/html response, so browsers parse injected tags as markup. A public config_nonce from any page containing a form and interaction by an unauthenticated visitor are required; authenticated visitors are not affected.
The record
- CVE
- CVE-2026-4406
- Published
- Apr 7, 2026
- Updated
- Apr 7, 2026
- Vendor
- Rocketgenius
- Product
- Gravity Forms
- Classifications
- CWE-79, T1204.001
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Apr 7, 2026CVE publishedPublication date reported by the CVE source.
- Apr 7, 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 <=2.9.30
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
- CVE-2026-4406 Gravity Forms reflected XSS proof of conceptproof of concept · demonstrated
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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