CVE-2026-96367 in Webform Plugin
Summary
by MITRE • 10/22/2026
Privilege Defined With Unsafe Actions vulnerability in Drupal Webform allows Stored XSS. This issue affects Webform versions: from 0.0.0 to 6.2.12, from 6.3.0 to 6.3.1.
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Analysis
by VulDB Data Team • 10/22/2026
The identified vulnerability represents a critical security flaw within the Drupal Webform module, specifically affecting version ranges spanning from early development releases up through versions 6.2.12 and 6.3.1. This issue is categorized under CWE-79, which denotes Improper Neutralization of Input During Web Page Generation commonly known as Cross-Site Scripting or XSS. The root cause lies in the improper handling of user-supplied input within the form processing logic, where data entered by users into web forms is not adequately sanitized before being rendered back to other users' browsers. This failure allows an attacker to inject malicious client-side scripts that execute in the context of a victim's session, thereby bypassing standard browser security models such as the same-origin policy.
From a technical perspective, the vulnerability stems from unsafe actions associated with privilege definition and input validation mechanisms within the Webform module. When a user submits a form containing specially crafted script tags or event handlers, the application fails to escape these characters properly before storing them in the database or rendering them on subsequent page loads. Consequently, when another user views the submitted form data, their browser interprets the injected code as legitimate content from the trusted Drupal site. This execution environment allows the malicious scripts to access cookies, session tokens, and other sensitive information protected by default browser policies, effectively granting the attacker a level of trust equivalent to that of the web application itself.
The operational impact of this stored XSS vulnerability is severe due to its persistent nature unlike reflected XSS which requires tricking a user into clicking a link, stored XSS remains active on the server until manually removed from the database. An authenticated or unauthenticated attacker depending on specific form configurations can compromise multiple users who view the affected forms. This leads to potential account takeover through session hijacking where stolen cookies allow impersonation of legitimate users including administrators with elevated privileges. Furthermore attackers may perform actions on behalf of victims such as modifying settings submitting fraudulent data or defacing web content which significantly undermines the integrity and availability of the Drupal-based website. The ability to execute arbitrary JavaScript also opens avenues for keylogging capturing sensitive keystrokes from forms containing passwords personal identification numbers or financial details thereby leading to direct data theft and regulatory compliance violations under frameworks like GDPR or HIPAA if applicable data is exposed.
Mitigation strategies must prioritize immediate patching as this vulnerability has been addressed in later versions of the Webform module beyond 6.2.12 and 6.3.1 administrators should upgrade to the latest stable release available for their Drupal version branch to ensure all known security patches are applied if upgrading is not immediately feasible temporary workarounds include implementing strict input validation at the application layer using allowlists rather than blocklists to filter out potentially dangerous characters such as script tags event handlers and javascript URIs. Additionally deploying a Web Application Firewall can provide an additional layer of defense by detecting and blocking common XSS payloads before they reach the vulnerable code paths though this should not be relied upon as a primary solution since WAFs may have false negatives or performance overheads. Security headers like Content-Security-Policy with strict directives regarding script sources can also help mitigate the impact even if an injection occurs by preventing unauthorized scripts from executing thereby reducing the blast radius of any successful exploitation attempt.
This vulnerability aligns with MITRE ATT&CK technique T1059 which covers Command and Scripting Interpretation specifically within web browsers via JavaScript execution it exemplifies how input validation failures can lead to significant security breaches in content management systems that rely heavily on user-generated content. Organizations utilizing Drupal Webform must treat this issue with high priority given the widespread adoption of the platform and the potential for large-scale compromise through stored persistent attacks that do not require complex social engineering beyond simply submitting a malicious form entry which could be automated at scale to maximize impact across multiple targets within an organization or public-facing service.