CVE-2026-28020: High Vulnerability in ThemeREX Chroma

CVE-2026-28020 is a high-severity vulnerability affecting the ThemeREX Chroma theme. This vulnerability allows improper control of filename for include/require statements in PHP programs, specifically leading to local file inclusion. The vulnerability impacts versions of Chroma from n/a to 1.11 and was first published on March 5, 2026.

The CVSS score for this vulnerability is 8.1, categorized as high severity. The risk to organizations includes potential unauthorized access to sensitive files, which could lead to further exploitation or data breaches. Given the nature of the vulnerability, organizations using the affected versions should prioritize patching immediately.

As of now, there is no public evidence of exploitation or proof of concept available. However, organizations should remain vigilant and monitor for potential risks associated with this vulnerability.

Urgency for defenders is high, and immediate action is recommended to protect systems against possible threats that could exploit this vulnerability.

Vulnerability Details

The vulnerability is classified under CWE-98, indicating a failure to properly validate filenames. This type of vulnerability can lead to significant security issues, especially in PHP applications where local file inclusion can expose sensitive data.

The attack vector is classified as network-based, with high attack complexity and no privileges or user interactions required. This means that attackers can exploit the vulnerability remotely, making it even more critical for organizations to address it.

Technical Analysis

The root cause of CVE-2026-28020 stems from inadequate controls over filenames used in PHP include/require statements, allowing attackers to include arbitrary files. This could lead to unauthorized reading or modification of sensitive files on the server.

The attack vector is network-based, and the complexity is deemed high due to the specific conditions that need to be met for the attack to be successful. No privileges are required, and user interaction is not necessary, making it easier for attackers to exploit.

The potential impacts include high confidentiality, integrity, and availability impacts, as attackers could access sensitive data, modify files, or disrupt services.

Risk & Impact Analysis

The vulnerability presents a real-world risk to organizations using ThemeREX Chroma. Attackers may leverage this vulnerability to gain unauthorized access to sensitive information, leading to data breaches and potential compliance issues.

The blast radius of this vulnerability could be significant, as it affects all installations of the Chroma theme up to version 1.11. Organizations should assess their exposure and prioritize patching to mitigate potential threats.

The urgency for remediation is high, given the high CVSS score and the potential for exploitation. Organizations should schedule remediation as a priority to protect their systems.

Exploitation Status

Affected Versions

This vulnerability affects all versions of ThemeREX Chroma up to version 1.11. Organizations should ensure they are using a patched version to avoid exposure to this vulnerability.

Mitigation & Remediation

Organizations should prioritize applying the latest security patches for ThemeREX Chroma. If a patch is unavailable, consider disabling the affected theme or implementing additional security measures to restrict file access.

For more comprehensive security, organizations may consider penetration testing to identify and remediate similar vulnerabilities.

Detection Guidance

Monitor server logs for unusual file access patterns that could indicate exploitation attempts. Look for any unauthorized file inclusions or modifications that may occur as a result of this vulnerability.

AppSecure Threat Intelligence Insight

CVE-2026-28020 represents a significant risk for web applications that utilize PHP. Security teams should learn from this incident and enhance their application security posture through effective code reviews and regular security assessments.

This vulnerability emphasizes the importance of validating user input and sanitizing file paths to prevent similar issues in the future. Organizations may also benefit from a structured vulnerability management program to enhance their overall security framework.

For organizations using cloud services, implementing cloud penetration testing can further help identify potential vulnerabilities within their applications.

Lastly, organizations should stay informed about emerging threats and vulnerabilities, as proactive measures are essential in maintaining a robust security posture.