Authenticated RCE via unchecked remote ZIP extraction
Published Apr 18, 2026 · Updated Apr 18, 2026
Arbitrary file upload in CMP – Coming Soon & Maintenance Plugin 4.1.16 and earlier allows remote authenticated users to execute PHP code. The cmp_theme_update_install AJAX action downloads a ZIP from a user-supplied URL without validating its content and extracts it into the web-accessible wp-content/plugins/cmp-premium-themes directory. A valid administrator nonce and administrator-level access are required; Editor access alone cannot reach the action, and successful extraction yields server-side code execution.
Summary
What happened
Arbitrary file upload in CMP – Coming Soon & Maintenance Plugin 4.1.16 and earlier allows remote authenticated users to execute PHP code. The cmp_theme_update_install AJAX action downloads a ZIP from a user-supplied URL without validating its content and extracts it into the web-accessible wp-content/plugins/cmp-premium-themes directory. A valid administrator nonce and administrator-level access are required; Editor access alone cannot reach the action, and successful extraction yields server-side code execution.
The record
- CVE
- CVE-2026-6518
- Published
- Apr 18, 2026
- Updated
- Apr 18, 2026
- Vendor
- NiteoThemes
- Product
- CMP – Coming Soon & Maintenance Plugin
- Classifications
- CWE-434, T1190
- Attack vector
- network
- Privileges
- admin
Timeline
How it unfolded
- Apr 18, 2026CVE publishedPublication date reported by the CVE source.
- Apr 18, 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 <=4.1.16
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
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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