Unauthenticated code execution via filename normalization bypass
Published Aug 21, 2026 · Updated Aug 21, 2026
Code injection in Drag and Drop Multiple File Upload for Contact Form 7 before 1.3.9.9 allows remote attackers to execute server code. The upload handler strips control characters from a filename but does not revalidate the resulting name, allowing a blocked file type to become executable. No authentication is required, but exploitation requires a non-default form-field configuration and a web server that honors per-directory configuration overrides.
Summary
What happened
Code injection in Drag and Drop Multiple File Upload for Contact Form 7 before 1.3.9.9 allows remote attackers to execute server code. The upload handler strips control characters from a filename but does not revalidate the resulting name, allowing a blocked file type to become executable. No authentication is required, but exploitation requires a non-default form-field configuration and a web server that honors per-directory configuration overrides.
The record
- CVE
- CVE-2026-18781
- Published
- Aug 21, 2026
- Updated
- Aug 21, 2026
- Vendor
- Glen Don Mongaya
- Product
- Drag and Drop Multiple File Upload for Contact Form 7
- Classifications
- CWE-94, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 21, 2026CVE publishedPublication date reported by the CVE source.
- Aug 21, 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 <1.3.9.9
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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