CVE-2026-27537 in Popup Plugin
Summary
by MITRE • 08/13/2026
Unauthenticated Cross Site Scripting (XSS) in Popup by Supsystic <= 1.11.2 versions.
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Analysis
by VulDB Data Team • 08/13/2026
The vulnerability under examination represents an unauthenticated cross site scripting flaw within the Popup plugin by Supsystic affecting versions up to and including 1.11.2. This security weakness resides in the plugin's handling of user input within popup functionality, creating a pathway for malicious actors to inject arbitrary javascript code into web pages viewed by unsuspecting users. The vulnerability specifically impacts the popup creation and rendering mechanisms where user-provided content fails to undergo proper sanitization before being displayed.
The technical implementation of this flaw stems from insufficient input validation and output encoding practices within the plugin's codebase. When administrators or users create popups containing dynamic content, the system does not adequately filter or escape special characters that could be interpreted as executable javascript code. This weakness allows attackers to inject malicious scripts through parameters such as popup titles, content fields, or configuration settings that are then rendered without proper sanitization. The vulnerability operates at the application layer and can be exploited by any user with access to the plugin's administrative interface or by leveraging other attack vectors that allow input manipulation.
The operational impact of this vulnerability extends beyond simple script execution, creating potential for data theft, session hijacking, and further exploitation within the affected web environment. An attacker could craft malicious popup content that executes when users view the page, potentially stealing cookies, session tokens, or other sensitive information from authenticated users. The unauthenticated nature of the exploit means that even users without administrative privileges could potentially leverage this vulnerability if they have the ability to create or modify popup content. This weakness can be particularly dangerous in multi-user environments where less privileged users might gain access to administrative functions through other vulnerabilities.
Mitigation strategies should focus on immediate patching of the affected plugin versions, with administrators upgrading to the latest available release that contains the necessary security fixes. The implementation of proper input validation and output encoding practices must be enforced throughout the application codebase, ensuring that all user-supplied content undergoes thorough sanitization before being rendered. Security headers such as Content Security Policy should be implemented to provide additional protection against script injection attacks. Organizations should also consider implementing web application firewalls and monitoring systems to detect potential exploitation attempts. This vulnerability aligns with CWE-79 which specifically addresses cross site scripting vulnerabilities, and maps to ATT&CK technique T1059.007 for command and scripting interpreter. Regular security audits and code reviews focusing on input validation mechanisms should be conducted to prevent similar issues in other components of the web application stack.