CVE-2026-4559 in Image Photo Gallery Final Tiles Grid Plugin
Summary
by MITRE • 08/22/2026
The Image Photo Gallery Final Tiles Grid plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'delay' shortcode attribute in all versions up to, and including, 3.6.12 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.
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Analysis
by VulDB Data Team • 08/22/2026
The Image Photo Gallery Final Tiles Grid plugin for WordPress contains a critical security flaw affecting all versions up to and including 3.6.12. This vulnerability is classified as a Stored Cross-Site Scripting issue, which corresponds to CWE-79 in the Common Weakness Enumeration framework. The root cause of this weakness lies in insufficient input sanitization and output escaping mechanisms within the plugin's codebase. Specifically, the flaw resides in the handling of the delay shortcode attribute. When users or administrators configure gallery settings using shortcodes, the system fails to properly validate or escape special characters before storing them in the database. This lack of rigorous data validation allows malicious actors to inject executable JavaScript code directly into the site's content structure.
The operational impact of this vulnerability is significant because it enables authenticated attackers with Contributor-level access and above to execute arbitrary web scripts within the context of other users' browsers. Unlike reflected XSS, where the payload must be delivered via a link, stored XSS persists on the server side. Once an attacker injects malicious code through the delay attribute, that script becomes part of the page content itself. Consequently, every user who visits the affected page will have their browser execute the injected scripts automatically. This persistence makes the attack highly effective for long-term exploitation, such as session hijacking, credential theft, or defacement, without requiring further interaction from the attacker after the initial injection.
From a threat intelligence perspective, this vulnerability aligns with MITRE ATT&CK technique T1059.007, which covers JavaScript execution in web browsers. The attack vector leverages the trust that users place in legitimate websites to compromise their sessions or personal data. Because the requirement is only Contributor-level access or higher, the barrier for exploitation is relatively low compared to vulnerabilities requiring Administrator privileges. This expands the potential pool of attackers who can exploit this flaw, including potentially compromised lower-privileged accounts or insiders with malicious intent. The ability to execute scripts in the context of other users poses a severe risk to data confidentiality and integrity across the entire WordPress installation.
To mitigate this vulnerability, site administrators should immediately update the Image Photo Gallery Final Tiles Grid plugin to version 3.6.13 or later, where these input sanitization and output escaping issues have been addressed by the developers. Until an update is applied, it is advisable to restrict user roles that can access gallery configuration settings to only those with Administrator privileges, thereby reducing the attack surface. Additionally, implementing a Web Application Firewall may help filter out malicious payloads attempting to exploit this specific shortcode attribute. Regular security audits and code reviews focusing on shortcodes are recommended to prevent similar input validation failures in other plugins or custom themes.