CVE-2026-81154 in Robo Gallery Plugin
Summary
by MITRE • 10/11/2026
The Robo Gallery WordPress plugin before 5.2.6 does not sanitise and escape image alt text before outputting it in one of its gallery layouts, allowing users with the Author role and above to perform Stored Cross-Site Scripting attacks that execute in the browser of any user viewing the affected gallery, including administrators.
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Analysis
by VulDB Data Team • 10/11/2026
The Robo Gallery WordPress plugin versions prior to 5.2.6 contain a critical input validation failure that permits stored cross-site scripting attacks through improper handling of image metadata. Specifically, the vulnerability resides in the processing of alt text fields associated with images within gallery layouts. When an administrator or author uploads media and provides descriptive alternative text for accessibility purposes, this data is not subjected to adequate sanitization or escaping mechanisms before being rendered into the HTML output of the gallery view. This oversight creates a direct pathway for malicious actors to inject executable JavaScript code under the guise of legitimate image descriptions. The flaw exploits the trust relationship between the web application and its users by leveraging the high privilege level required to create content, yet it impacts all viewers regardless of their access rights on the site.
From a technical perspective, this vulnerability is classified as CWE-79, which denotes Improper Neutralization of Input During Web Page Generation commonly known as Cross-site Scripting. The root cause lies in the absence of output encoding functions such as esc_attr or wp_kses when rendering the alt attribute values within the gallery templates. Because WordPress typically relies on developers to manually implement these security measures for custom post meta and image fields, a failure to do so results in raw user input being embedded directly into the DOM structure. When a victim with any browsing session active on the compromised site loads a page containing the maliciously crafted gallery, the browser interprets the injected script as part of the webpage content rather than static data. This execution context allows the attacker's code to run with the same privileges and permissions as the rest of the web application, effectively bypassing standard client-side security controls like Content Security Policy if not strictly configured.
The operational impact of this vulnerability is severe due to its stored nature. Unlike reflected XSS which requires social engineering to trick a user into clicking a malicious link, stored XSS persists on the server side until manually removed from the database or content repository. This means that every visitor who views the affected gallery becomes a potential victim without any additional interaction required beyond page load. Attackers can exploit this persistence to steal session cookies, hijack administrative sessions, deface websites by altering displayed content, or redirect users to phishing sites designed to harvest credentials. The ability for an attacker with Author-level access to compromise administrators highlights a significant privilege escalation risk within the WordPress ecosystem, potentially leading to full site takeover and further exploitation of backend systems connected to the compromised environment.
In terms of threat modeling, this vulnerability aligns with MITRE ATT&CK technique T1059.007, which covers JavaScript execution in web browsers as part of initial access or persistence strategies. The attacker leverages the application's own functionality against its users, turning a standard content management feature into an attack vector. This type of flaw is particularly dangerous because it exploits legitimate administrative workflows, making detection through traditional perimeter security tools difficult since the traffic appears to be normal user-generated content creation and consumption activity.
To mitigate this vulnerability, immediate action must be taken by updating the Robo Gallery plugin to version 5.2.6 or later where these input validation issues have been addressed. Site administrators should also audit existing gallery entries for any suspicious script tags embedded within alt text fields that may have been injected prior to patching. Implementing a Web Application Firewall with rules capable of detecting and blocking XSS payloads in form submissions can provide an additional layer of defense during the transition period. Furthermore, enforcing strict Content Security Policy headers on WordPress sites helps limit the impact of any successful injection by restricting script execution sources and preventing unauthorized data exfiltration to external domains. Regular security audits focusing on input sanitization and output escaping practices are essential for maintaining robust defenses against similar vulnerabilities in other plugins or custom code components.