CVE-2026-16618: CWE-434 Unrestricted Upload of File with Dangerous Type in Improve SEO
The Improve SEO WordPress plugin up to version 2.0.11 improperly validates uploaded files by only checking the file content type but saving files with attacker-controlled extensions in a publicly accessible directory. This allows unauthenticated users to upload executable PHP files, potentially leading to remote code execution on the affected site.
AI Analysis
Technical Summary
CVE-2026-16618 is a vulnerability in the Improve SEO WordPress plugin through version 2.0.11 where the plugin fails to properly validate uploaded files. It only checks the MIME content type but writes the file using the attacker-supplied extension into a web-accessible directory. This flaw enables unauthenticated attackers to upload malicious PHP files and execute arbitrary code remotely on the server hosting the plugin.
Potential Impact
Successful exploitation allows unauthenticated attackers to upload executable PHP files, resulting in remote code execution. This can lead to full compromise of the affected web server and potentially the underlying infrastructure.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, restrict file upload permissions, disable or limit the plugin's upload functionality, or implement web server rules to block execution of uploaded files in the plugin's upload directory.
CVE-2026-16618: CWE-434 Unrestricted Upload of File with Dangerous Type in Improve SEO
Description
The Improve SEO WordPress plugin up to version 2.0.11 improperly validates uploaded files by only checking the file content type but saving files with attacker-controlled extensions in a publicly accessible directory. This allows unauthenticated users to upload executable PHP files, potentially leading to remote code execution on the affected site.
Affected software
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-16618 is a vulnerability in the Improve SEO WordPress plugin through version 2.0.11 where the plugin fails to properly validate uploaded files. It only checks the MIME content type but writes the file using the attacker-supplied extension into a web-accessible directory. This flaw enables unauthenticated attackers to upload malicious PHP files and execute arbitrary code remotely on the server hosting the plugin.
Potential Impact
Successful exploitation allows unauthenticated attackers to upload executable PHP files, resulting in remote code execution. This can lead to full compromise of the affected web server and potentially the underlying infrastructure.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, restrict file upload permissions, disable or limit the plugin's upload functionality, or implement web server rules to block execution of uploaded files in the plugin's upload directory.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- WPScan
- Date Reserved
- 2026-07-22T14:45:28.693Z
- Cvss Version
- null
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a7187d1bf32cb7a34e19b50
Added to database: 08/04/2026, 06:33:53 UTC
Last enriched: 08/04/2026, 06:52:55 UTC
Last updated: 08/04/2026, 07:58:13 UTC
Views: 6
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