Contributor-level stored XSS via mf_form_id transformation
Published Aug 25, 2026 · Updated Aug 25, 2026
Stored XSS in Roxnor MetForm 4.1.8 and earlier allows remote authenticated users to inject scripts through the mf_form_id widget setting. The setting reaches output without sufficient sanitization or escaping; a tag-free payload bypasses Elementor's wp_kses_post filter, and MetForm's str_replace logic creates a JavaScript template-literal delivery path. Contributor-level access is required, and the stored script executes whenever a user opens the injected page, enabling actions in that visitor's browser context.
Summary
What happened
Stored XSS in Roxnor MetForm 4.1.8 and earlier allows remote authenticated users to inject scripts through the mf_form_id widget setting. The setting reaches output without sufficient sanitization or escaping; a tag-free payload bypasses Elementor's wp_kses_post filter, and MetForm's str_replace logic creates a JavaScript template-literal delivery path. Contributor-level access is required, and the stored script executes whenever a user opens the injected page, enabling actions in that visitor's browser context.
The record
- CVE
- CVE-2026-18100
- Published
- Aug 25, 2026
- Updated
- Aug 25, 2026
- Vendor
- Roxnor
- Product
- MetForm
- Classifications
- CWE-79, T1059.007
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Aug 25, 2026CVE publishedPublication date reported by the CVE source.
- Aug 25, 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 <=4.1.8
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
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Technologies
Your stack
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Your stack
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