CVE-2026-39745 in Contact Form to DB Plugin
Summary
by MITRE • 10/06/2026
Unauthenticated Cross Site Scripting (XSS) in Contact Form to DB by BestWebSoft <= 1.7.6 versions.
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Analysis
by VulDB Data Team • 10/06/2026
The vulnerability identified as an unauthenticated cross-site scripting flaw within the contact form functionality of BestWebSoft plugins, specifically affecting versions up to and including 1.7.6, represents a significant security risk for websites relying on these components. This issue stems from insufficient input validation and sanitization mechanisms when processing user-submitted data through the public-facing contact forms. Because the vulnerability is unauthenticated, any individual with access to the website can exploit it without needing valid credentials or prior authorization, thereby lowering the barrier to entry for attackers significantly. The core technical flaw lies in the application's failure to properly encode or escape special characters within user inputs before they are stored in the database and subsequently rendered back into HTML contexts on other pages or potentially even on the submission confirmation page itself. This lack of proper output encoding allows malicious scripts, typically written in JavaScript, to be injected directly into the web page content served to legitimate users.
From a technical perspective, this vulnerability aligns with CWE-79, which categorizes improper neutralization of input during web page generation as Cross-site Scripting (XSS). The attack vector involves an attacker crafting a malicious payload containing executable JavaScript code and submitting it through the contact form fields such as name, email, or message body. When another user visits the affected page where this data is displayed, their browser executes the injected script in the context of the vulnerable website's domain. This scenario falls under stored XSS because the malicious content persists within the application's database rather than being transient like reflected XSS. The persistence ensures that every visitor to the compromised area becomes a potential victim, amplifying the impact far beyond a single interaction with the form.
The operational impact of this vulnerability is severe and multifaceted. Attackers can utilize the executed JavaScript to perform session hijacking by stealing cookies or authentication tokens stored in local storage if present on the page. This enables them to impersonate legitimate users, including administrators, gaining unauthorized access to sensitive areas of the website. Furthermore, attackers may redirect victims to phishing sites designed to steal credentials from other services through credential harvesting forms that mimic trusted interfaces. The vulnerability also facilitates defacement attacks where malicious content is displayed to visitors, damaging the organization's reputation and trustworthiness. In more advanced scenarios, the script can be used to launch drive-by downloads or exploit browser vulnerabilities if combined with other techniques, although this requires additional conditions beyond just the XSS flaw itself.
This incident maps directly to several tactics within the MITRE ATT&CK framework for web applications. It corresponds primarily to T1059, Command and Scripting Interpreter, specifically JavaScript execution in a browser context. The persistence aspect aligns with TA0003 Persistence as the malicious payload remains stored in the database. Additionally, it relates to TA0006 Credential Access through techniques like Steal Web Session Cookie or Harvest Credentials via Phishing if used for credential theft purposes. Understanding these mappings helps security teams prioritize remediation efforts based on standard threat intelligence frameworks and recognize the broader implications of seemingly simple input validation failures.
Mitigation strategies must focus on implementing robust defense-in-depth measures immediately. The primary fix involves applying a patch from BestWebSoft that addresses the specific input handling logic in versions newer than 1.7.6, ensuring all user inputs are strictly validated against expected formats and sanitized using context-aware encoding before being stored or rendered. Developers should adopt whitelisting approaches for allowed characters rather than blacklisting dangerous ones to prevent bypasses through obfuscation techniques. Implementing Content Security Policy headers can also mitigate the impact by restricting where scripts can be loaded from, thereby preventing execution of injected payloads even if they are successfully inserted into the DOM. Regular security audits and static code analysis tools should be integrated into the development lifecycle to detect such vulnerabilities early before deployment to production environments.