CVE-2026-28020 is a Local File Inclusion (LFI) vulnerability found in the ThemeREX Chroma WordPress theme, specifically affecting versions up to 1.11. The vulnerability arises from improper control over the filename parameter used in PHP include or require statements. This flaw enables an attacker to manipulate the input that determines which file is included by the PHP script, allowing them to include arbitrary files from the local filesystem. Such an inclusion can lead to sensitive information disclosure (e.g., configuration files, password files), execution of malicious code if the included files contain executable PHP code, or even full site compromise. The vulnerability does not have a CVSS score yet, but it is classified as a serious security issue due to the nature of LFI vulnerabilities. No known public exploits have been reported, but the risk remains significant given the widespread use of WordPress and third-party themes like Chroma. The vulnerability affects all installations using the vulnerable versions of the ThemeREX Chroma theme, particularly those that do not have additional input validation or security controls in place. The absence of a patch link suggests that a fix may not yet be publicly available, emphasizing the need for immediate mitigation steps by administrators. The vulnerability was reserved and published in early 2026, indicating it is a recent discovery. Attackers exploiting this vulnerability could gain unauthorized access to sensitive data or execute arbitrary code, impacting the confidentiality, integrity, and availability of affected systems.

The impact of CVE-2026-28020 can be severe for organizations using the vulnerable ThemeREX Chroma theme. Successful exploitation can lead to unauthorized disclosure of sensitive files, including configuration files containing database credentials or API keys, which can facilitate further attacks. Attackers may also execute arbitrary PHP code by including malicious files, potentially leading to full site takeover, defacement, or use of the compromised server as a pivot point for lateral movement within a network. This can result in data breaches, service disruption, reputational damage, and financial losses. Since WordPress powers a significant portion of websites globally, and themes like Chroma are widely used, the vulnerability poses a broad risk. The lack of known exploits in the wild currently reduces immediate risk but does not eliminate the threat, as attackers often develop exploits rapidly after disclosure. Organizations with public-facing WordPress sites using this theme are particularly vulnerable, especially if they lack web application firewalls or other protective measures. The vulnerability can also be leveraged to bypass authentication or escalate privileges if combined with other vulnerabilities or misconfigurations.

1. Immediately update the ThemeREX Chroma theme to the latest version once a patch is released by the vendor. Monitor official ThemeREX channels for updates. 2. In the absence of an official patch, apply manual code review and hardening: sanitize and validate all inputs controlling file inclusion paths to ensure only intended files can be included. 3. Implement web application firewalls (WAFs) with rules to detect and block suspicious file inclusion attempts. 4. Restrict PHP include paths using configuration directives (e.g., open_basedir) to limit accessible directories. 5. Disable unnecessary PHP functions such as allow_url_include to prevent remote file inclusion variants. 6. Regularly audit and monitor web server logs for unusual access patterns or attempts to exploit file inclusion. 7. Employ the principle of least privilege for web server and application file permissions to minimize the impact of a successful attack. 8. Consider isolating WordPress instances in containerized or sandboxed environments to limit lateral movement. 9. Educate development and operations teams about secure coding practices related to file inclusion and input validation. 10. Backup website data regularly to enable quick recovery in case of compromise.