CVE-2026-58587 in Canvas
Summary
by MITRE • 07/11/2026
Improper Neutralization of Input During Web Page Generation ("Cross-site Scripting") vulnerability in Drupal Drupal Canvas allows Cross-Site Scripting (XSS). This issue affects Drupal Canvas versions: from 0.0.0 to 1.4.2, from 1.5.0 to 1.5.2, from 1.6.0 to 1.6.1, from 1.7.0 to 1.7.1.
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Analysis
by VulDB Data Team • 07/11/2026
This vulnerability represents a classic cross-site scripting flaw that undermines the security of web applications by allowing malicious actors to inject client-side scripts into web pages viewed by other users. The issue specifically impacts Drupal Canvas, a content management system component that generates dynamic web content, where input validation mechanisms fail to properly sanitize user-provided data before rendering it within HTML contexts. The vulnerability manifests when the application processes user input without adequate neutralization, creating opportunities for attackers to execute malicious scripts in the context of other users' browsers.
The technical flaw stems from insufficient input sanitization during web page generation processes, where Drupal Canvas fails to adequately escape or filter special characters that could be interpreted as HTML or JavaScript code. This improper neutralization creates a pathway for attackers to inject malicious payloads through various input vectors including form fields, URL parameters, or API endpoints that feed into the content rendering pipeline. The vulnerability affects multiple version ranges, indicating a persistent flaw in the input handling mechanisms across different release branches, suggesting either inadequate testing procedures or fundamental architectural issues in how user input is processed and rendered.
The operational impact of this XSS vulnerability extends beyond simple script execution to potentially enable sophisticated attacks including session hijacking, credential theft, and data exfiltration. An attacker could exploit this vulnerability to steal user sessions, modify content displayed to other users, redirect them to malicious sites, or perform actions on their behalf within the application context. The widespread version range affected suggests that organizations running these Drupal Canvas installations face significant risk exposure, particularly in environments where users have varying levels of privileges or where sensitive data is processed through the affected components.
Organizations should implement comprehensive input validation and output encoding mechanisms to address this vulnerability, following established security practices such as those outlined in the CWE-79 category for cross-site scripting. The remediation strategy should include proper HTML escaping of all user-provided content before rendering, implementation of Content Security Policies to limit script execution, and regular security testing to identify similar vulnerabilities. Additionally, organizations should consider implementing web application firewalls and monitoring systems that can detect and prevent exploitation attempts. According to ATT&CK framework, this vulnerability maps to T1566 for initial access through malicious input and T1059 for command and control through script execution, emphasizing the need for layered defensive measures to protect against both exploitation and subsequent attack phases.
The vulnerability underscores the critical importance of proper input validation in web applications and demonstrates how seemingly simple flaws can create significant security risks. Regular security updates and patch management procedures should be prioritized to address such vulnerabilities promptly. Organizations should also conduct thorough security assessments to identify similar issues in other application components, as this vulnerability likely represents a pattern rather than an isolated incident in the application's input handling processes.