CVE-2026-100510 in Post and Page Builder Plugin
Summary
by MITRE • 09/30/2026
Unauthenticated Cross Site Scripting (XSS) in Post and Page Builder by BoldGrid <= 1.27.14 versions.
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Analysis
by VulDB Data Team • 09/30/2026
The vulnerability identified as an unauthenticated cross-site scripting flaw within the Post and Page Builder plugin for WordPress, specifically affecting versions up to 1.27.14, represents a significant security risk due to its lack of authentication requirements. This characteristic allows any remote attacker with network access to exploit the weakness without needing valid credentials or prior interaction with an authenticated user session. The core technical flaw stems from insufficient input validation and sanitization mechanisms within the plugin's handling of user-supplied data. When processing requests, the application fails to properly neutralize special characters that could be interpreted as executable script code by a web browser. This oversight permits attackers to inject malicious JavaScript payloads directly into HTTP responses that are subsequently rendered in the victim's browser environment.
From a technical perspective, this vulnerability aligns with CWE-79, which classifies improper neutralization of input during web page generation known as cross-site scripting. The attack vector typically involves manipulating query parameters or form inputs associated with the plugin’s rendering engine. Because the flaw is unauthenticated, the exploitation process does not require social engineering tactics to trick an administrator into clicking a malicious link while logged in. Instead, an attacker can craft a URL containing the malicious script payload and distribute it through various channels such as email, forums, or other websites. When a victim visits this crafted page, their browser executes the injected code within the context of the vulnerable website’s domain.
The operational impact of this vulnerability is severe because cross-site scripting attacks enable attackers to perform actions on behalf of the user without their knowledge. In the context of WordPress administration tools like Post and Page Builder, successful exploitation can lead to session hijacking if cookies are not properly secured with flags such as HttpOnly or Secure. Attackers can steal administrative sessions, leading to full compromise of the website’s backend. Furthermore, the injected scripts can modify page content dynamically, deface the site by altering visual elements, or redirect users to phishing sites designed to harvest credentials from other visitors. The ability to execute arbitrary JavaScript also allows for keylogging capabilities, potentially capturing sensitive information entered into forms on the compromised site.
This vulnerability maps directly to MITRE ATT&CK technique T1059.007, which covers execution of scripts via web browsers as part of client-side code injection attacks. It also relates to T1189, drive-by compromise, where users are lured into visiting a malicious page that exploits the browser and any installed plugins or extensions. The unauthenticated nature of this flaw places it in a high-risk category because it lowers the barrier for entry significantly compared to authenticated vulnerabilities. Security researchers emphasize that such flaws often arise from developers assuming that certain endpoints require authentication, thereby neglecting basic input sanitization practices that should be applied universally regardless of access level.
Mitigation strategies must prioritize immediate patching as the primary defense mechanism. Administrators running Post and Page Builder versions 1.27.14 or earlier are advised to upgrade to the latest patched version immediately upon availability from BoldGrid. Until an update is deployed, temporary mitigations include implementing a Web Application Firewall that can detect and block common XSS patterns in HTTP requests. Additionally, ensuring that Content Security Policy headers are correctly configured can help mitigate the impact of successful injection attempts by restricting the sources from which scripts can be loaded or executed. Regular security audits and code reviews focusing on input validation logic are essential to prevent similar vulnerabilities in future releases. Organizations should also monitor for indicators of compromise related to unusual script injections or unauthorized content modifications within their WordPress installations.