CVE-2026-73238 in Allura
Summary
by MITRE • 08/12/2026
XSS vulnerability in code display in Apache Allura.
This issue affects Apache Allura: before 1.19.1.
Users are recommended to upgrade to version 1.19.1, which fixes the issue.
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Analysis
by VulDB Data Team • 08/12/2026
The vulnerability in Apache Allura represents a cross-site scripting flaw that specifically impacts the code display functionality within the application's user interface. This security weakness allows malicious actors to inject arbitrary JavaScript code into the code display components, potentially compromising user sessions and enabling unauthorized actions. The vulnerability exists in versions prior to 1.19.1, making all earlier releases susceptible to exploitation through carefully crafted input that bypasses standard sanitization mechanisms.
The technical implementation of this XSS vulnerability stems from insufficient input validation and output encoding within the code rendering subsystem. When users submit code snippets or view existing code within Allura's interface, the application fails to properly sanitize user-supplied content before displaying it in the browser context. This inadequate filtering allows attackers to embed malicious script tags or other harmful payloads that execute within the victim's browser session. The flaw specifically manifests when the application processes code blocks containing special characters that can be interpreted as HTML or JavaScript markup without proper escaping or sanitization.
The operational impact of this vulnerability extends beyond simple data theft, as it can enable attackers to perform session hijacking, redirect users to malicious websites, or inject persistent malware into the application environment. An attacker could exploit this weakness to execute commands on behalf of authenticated users, potentially gaining access to sensitive project information, source code repositories, or administrative functions within the Allura platform. The vulnerability affects any user who views affected code displays, making it particularly dangerous in collaborative environments where multiple developers interact with shared code repositories.
This issue aligns with CWE-79, which categorizes cross-site scripting vulnerabilities as a fundamental weakness in input validation and output encoding. From an ATT&CK framework perspective, this vulnerability maps to techniques involving code injection and credential access, potentially enabling adversaries to escalate privileges within the application environment. The remediation strategy focuses on implementing proper input sanitization and output encoding mechanisms that prevent malicious content from being executed in browser contexts. Organizations should prioritize upgrading to Apache Allura version 1.19.1 or later, which includes patches addressing the specific sanitization gaps in the code display functionality.
The security implications of this vulnerability underscore the critical importance of robust input validation in web applications, particularly those handling user-generated content in code repositories. Proper implementation of Content Security Policy headers and additional output encoding layers can provide defense-in-depth measures against similar vulnerabilities. Regular security assessments and automated scanning of application components help identify potential injection points before they can be exploited by malicious actors in the wild.