CVE-2026-50229 Scanner

Apache Tomcat is a widely used open-source web server and servlet container developed by the Apache Software Foundation. It implements several Java EE specifications, such as Java Servlet, JavaServer Pages (JSP), and more, serving as a platform for web applications. Businesses worldwide rely on Tomcat for hosting and deploying Java applications due to its robustness and versatility. IT professionals, developers, and system administrators frequently use Tomcat in enterprise environments and for educational purposes. Its ease of integration and configuration makes it popular for both small and large scale operations requiring Java support.

The vulnerability in question is a Cross-Site Scripting (XSS) flaw found in Apache Tomcat's number guess JSP example application. Cross-Site Scripting allows attackers to inject malicious scripts into web pages viewed by other users, which can execute in their browsers. This vulnerability stems from improper neutralization of script-related HTML tags, enabling an attacker to perform unauthorized actions in the context of the affected web application. XSS vulnerabilities are a severe threat to web security, potentially compromising user data and application integrity. Addressing this vulnerability involves strict input validation and context-sensitive encoding to avoid script injection.

The technical details of the vulnerability include a lack of adequate escaping and filtering of user-supplied input in a specific JSP file within Tomcat's examples directory. The vulnerable end point is an example number guessing game, where the 'guess' and 'hint' parameters can be exploited. Attackers can craft a request that includes script tags in one of these parameters, which, when executed, will display an alert with the document's domain. The web page's failure to sanitize these inputs adequately permits the execution of malicious JavaScript, which could be leveraged for a range of attacks, such as session hijacking or web defacements.

If exploited by a malicious actor, this XSS vulnerability could allow attackers to execute arbitrary scripts in the browser of unsuspecting users. This could lead to sensitive information disclosure, theft of user cookies, or even unauthorized actions being performed on behalf of the user. Affected users could potentially be redirected to harmful sites, or have their browser perform unauthorized transactions. Moreover, repeated exploitation could erode user trust in the site, resulting in reputational damage and potential financial losses for affected organizations. Mitigation efforts should therefore focus on updating affected systems and reviewing input handling mechanisms within applications.

REFERENCES

• https://lists.apache.org/thread/wlt2no8bw45zl1w8byop4zfqphldf5j0
• https://www.cve.org/CVERecord?id=CVE-2026-50229
• https://tomcat.apache.org/security-11.html
• https://www.herodevs.com/vulnerability-directory/cve-2026-50229