CVE-2026-4413 in Concert
Summary
by MITRE • 10/19/2026
IBM Concert 1.0 through 3.0.0 is vulnerable to cross-site scripting. This vulnerability allows an unauthenticated attacker to embed arbitrary JavaScript code in the Web UI thus altering the intended functionality potentially leading to credentials disclosure within a trusted session.
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Analysis
by VulDB Data Team • 10/19/2026
The security flaw identified in IBM Concert versions 1.0 through 3.0.0 represents a critical web application vulnerability classified as Cross-Site Scripting, commonly referred to by its acronym XSS. This specific instance falls under the category of stored or persistent cross-site scripting depending on how the input is handled within the Web UI, though the core mechanism involves the injection of malicious client-side scripts into pages viewed by other users. The vulnerability arises from insufficient validation and sanitization of user-supplied data before it is rendered in the browser environment. When an attacker submits crafted input containing JavaScript code through any accessible field or parameter within the IBM Concert interface, the application fails to neutralize these characters effectively. Consequently, when another user accesses a page that displays this malicious content, the browser executes the embedded script as if it were part of the legitimate web application source code. This behavior violates the fundamental security principle of same-origin policy, allowing the injected scripts to interact with the DOM and access sensitive data associated with the current session context.
From an operational perspective, the impact of this vulnerability is severe due to its unauthenticated nature. An attacker does not need valid credentials or prior authentication to exploit this flaw, significantly lowering the barrier for entry. Once executed within a victim's browser, the malicious script can perform actions on behalf of that user while they are logged into IBM Concert. This capability enables credential harvesting through techniques such as keylogging, form field interception, or session cookie theft. If an attacker captures valid authentication tokens or credentials, they gain unauthorized access to the system with the privileges held by the compromised account. Furthermore, because the script runs within a trusted domain context, it can manipulate page content, redirect users to phishing sites, or perform state-changing actions such as modifying configurations or deleting data without user consent. This undermines both the confidentiality and integrity of the application's data and operations.
The technical classification of this vulnerability aligns with CWE-79: Improper Neutralization of Input During Web Page Generation, which is widely recognized in industry standards for web security flaws. In terms of offensive tactics, this exploitation vector maps to MITRE ATT&CK technique T1059.007: JavaScript, specifically within the context of client-side code execution and potentially T1556 if it involves modifying authentication mechanisms or credentials directly. The ability to execute arbitrary scripts in a trusted environment is a primary concern for modern web application security frameworks because it bypasses server-side controls that might otherwise restrict unauthorized access.
To mitigate this vulnerability, immediate remediation efforts should focus on implementing robust input validation and output encoding strategies across all entry points within the IBM Concert Web UI. Developers must ensure that any user-supplied data is strictly validated against a whitelist of expected characters before processing. More critically, when rendering dynamic content in HTML contexts, special attention must be paid to escaping or encoding potentially dangerous characters such as angle brackets, quotes, and ampersands using context-aware output encoding techniques. Implementing Content Security Policy headers can also provide an additional layer of defense by restricting the sources from which scripts are allowed to load and execute, thereby mitigating the impact even if some injection occurs. Upgrading to a patched version of IBM Concert where these input handling mechanisms have been corrected is the most effective long-term solution for organizations relying on this software infrastructure.