CVE-2026-22799 is a critical vulnerability affecting Emlog, an open-source website building system. This vulnerability allows authenticated attackers to exploit a REST API endpoint for media file uploads. The vulnerability arises due to inadequate validation of file types, extensions, and content at the endpoint (/index.php?rest-api=upload). This oversight enables attackers with valid API keys or admin session cookies to upload arbitrary files, including malicious PHP scripts. Once uploaded, these malicious files can be executed, resulting in remote code execution (RCE) on the target server, leading to full server compromise.
The severity level of this vulnerability is critical, with a CVSS score of 9.3. Such a high score indicates an urgent need for remediation, as it poses a significant threat to organizations using affected versions of Emlog. Organizations should prioritize patching immediately to prevent exploitation and mitigate potential risks.
As of now, there are no confirmed public exploits or known proof-of-concept (PoC) code available for this vulnerability. However, the potential for exploitation exists, particularly given the ease with which an attacker can gain access to an API key through administration access or by exploiting other vulnerabilities within the application. Therefore, organizations utilizing Emlog should take immediate steps to apply the available patches.
The publication date for this vulnerability was January 12, 2026, and it was last modified on January 21, 2026. Given its critical nature, organizations must remain vigilant and proactive in their security measures to protect their web applications.
With the potential for full server compromise, this vulnerability highlights the importance of proper validation and security measures for file uploads in web applications.
Vulnerability Details
Emlog is an open-source website building system. Emlog versions 2.6.1 and earlier expose a REST API endpoint for media file uploads. The endpoint fails to implement proper validation of file types, extensions, and content, allowing authenticated attackers (with a valid API key or admin session cookie) to upload arbitrary files (including malicious PHP scripts) to the server.
The CVSS score for this vulnerability is 9.3, indicating that it is critical. The attack vector is network-based, and the attack complexity is low, meaning that it requires minimal effort for an attacker to exploit it. The vulnerability has a high impact on confidentiality, integrity, and availability.
The affected product is Emlog, and the vendor is Emlog. The vulnerability was published on January 12, 2026, and the CWE classification is CWE-434, which pertains to the improper handling of file uploads.
Technical Analysis
The root cause of this vulnerability is the lack of sufficient validation in the REST API endpoint for media file uploads. Attackers can exploit this weakness by uploading files that the server does not properly verify, enabling them to execute arbitrary code.
The attack vector is network-based, as it relies on the ability to send requests to the public API endpoint. The attack complexity is low, as no special conditions are required beyond having a valid API key or session cookie. Privileges required are none, making this vulnerability particularly dangerous, as it can be exploited by any authenticated user.
User interaction is not required, and the impacts on confidentiality, integrity, and availability are all high, meaning that successful exploitation can lead to significant damage.
Risk & Impact Analysis
The real-world risk associated with CVE-2026-22799 is substantial, particularly for organizations using Emlog versions 2.6.1 and earlier. The ability for attackers to upload and execute arbitrary files can lead to complete server takeover, exposing sensitive data and compromising the entire web application.
Organizations must prioritize patching immediately. The attack vector being network-based means that it is easily exploitable from outside the organization's perimeter, increasing the urgency for remediation.
Failure to address this vulnerability could result in extensive damage, including data loss, unauthorized access to sensitive information, and potential legal ramifications due to data breaches.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
Emlog versions 2.6.1 and earlier are affected by this vulnerability. Organizations using these versions should take immediate action to apply the available patches.
Mitigation & Remediation
To mitigate the risk associated with CVE-2026-22799, organizations should apply the latest patches provided by Emlog. For detailed instructions on patching, refer to the vendor's resources.
Additionally, organizations can implement configuration hardening techniques to limit file upload capabilities or restrict upload types to safe formats. Network controls should also be established to monitor and filter incoming requests to the vulnerable endpoint.
Penetration testing should be considered to validate the effectiveness of the applied remediations.
Detection Guidance
Organizations should monitor logs for unusual file upload activities and look out for behavioral anomalies that may indicate exploitation attempts. Network signatures that capture requests to the vulnerable endpoint should be implemented, and system changes should be monitored for unauthorized modifications.
AppSecure Threat Intelligence Insight
CVE-2026-22799 represents a significant threat to web applications using Emlog. The nature of file uploads and remote code execution highlights the need for stringent validation processes. Security teams should take this opportunity to review their application security practices, ensuring that they have robust measures in place to prevent similar vulnerabilities.
Organizations are encouraged to adopt a comprehensive penetration testing methodology as part of their security strategy to not only address current vulnerabilities but to also anticipate and mitigate future risks.
This vulnerability serves as a reminder of the importance of secure coding practices and the need for ongoing security assessments.
For further insights on how to enhance your security posture, organizations can refer to resources on vulnerability management and API security.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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