Description

IBM API Connect 10.0.8.0 through 10.0.8.12 and 12.1.0.0 through 12.1.1.2 could allow a remote authenticated attacker to execute arbitrary JavaScript due to cross-site scripting. HTML content supplied by a provider is not sufficiently sanitized before it is displayed, which could allow script content to run in the user's browser.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "8.7",
  "pubDate": "2026-11-07T05:18:29.840Z",
  "pubdate": "2026-11-07T05:18:29.840Z",
  "executiveSummary": "This vulnerability is identified as a Stored Cross-Site Scripting (XSS) flaw affecting IBM API Connect. The issue arises from the insufficient sanitization of HTML content provided by users within the application interface.\nA remote authenticated attacker can leverage this vulnerability to inject and execute arbitrary JavaScript code within the context of a victim's browser session. By supplying malicious HTML or script content that is subsequently rendered by the application, an attacker can hijack user sessions, perform unauthorized actions on behalf of the user, or exfiltrate sensitive data.\nThe vulnerability impacts specific versions of IBM API Connect, specifically 10.0.8.0 through 10.0.8.12 and 12.1.0.0 through 12.1.1.2. The risk is significant for organizations that allow provider-supplied content, as it allows an authenticated actor with standard privileges to compromise the integrity of the administrative or developer portal sessions.\nSuccessful exploitation requires the attacker to be authenticated to the platform and have the capability to input or modify content that is rendered by other users, such as administrators or other portal users, without adequate server-side filtering.",
  "technicalDetails": "The vulnerability resides within the content rendering engine of IBM API Connect, which fails to implement robust input validation or output encoding mechanisms for HTML data supplied by content providers. When a provider submits data that includes HTML tags, the application stores this content in its backend database without stripping potentially malicious script elements, such as <script> blocks or event handlers (e.g., onload, onerror).\nThe attack flow begins when an authenticated attacker, operating as a provider, submits a crafted malicious payload into an input field that the application subsequently persists. When a legitimate user—such as an administrator or another developer—navigates to the interface where this stored content is displayed, the application reflects the unencoded, malicious HTML directly into the Document Object Model (DOM) of the victim's browser.\nBecause the application fails to perform context-aware output sanitization before rendering this data, the victim's browser interprets the injected JavaScript as legitimate, trusted content from the origin domain. This bypasses typical browser-based security controls by executing the script within the victim's authenticated session context.\nThe payload behavior is limited only by the attacker's ability to craft JavaScript. Common post-exploitation scenarios include the theft of Session IDs or CSRF tokens via document.cookie access, the redirection of the user to malicious external sites, or the automated execution of administrative actions within the IBM API Connect interface without the user's consent. This is particularly dangerous if the victim has elevated administrative privileges, as the malicious script can perform cross-site requests to perform configuration changes or exfiltrate API keys and sensitive configuration data.\nThis vulnerability is categorized as a failure to implement proper output encoding for user-supplied data in a web-based dashboard or portal context. Affected versions include 10.0.8.0 through 10.0.8.12 and 12.1.0.0 through 12.1.1.2. The lack of a Content Security Policy (CSP) further exacerbates the risk, allowing the browser to execute inline scripts that would otherwise be blocked by restrictive security headers.\nSince the application trust model assumes that content provided by authenticated entities is benign, the attack surface is exposed to any user account with permissions to update provider-facing documentation or portal content. Exploitation does not require elevated initial privileges, only the ability to supply content that is eventually viewed by other users of the management console or developer portal."
}