Description

IBM App Connect Enterprise 13.0.1.0 through 13.0.8.1, and 12.0.1.0 through 12.0.12.28 and IBM Integration Bus for z/OS 10.1.0.0 through 10.1.0.7 Toolkit could allow an authenticated user to cause a denial-of-service condition due to improper validation of XML entities.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "5.7",
  "pubDate": "2026-09-04T17:16:51.977Z",
  "pubdate": "2026-09-04T17:16:51.977Z",
  "executiveSummary": "This vulnerability involves an improper validation of XML entities within IBM App Connect Enterprise and IBM Integration Bus for z/OS.\nThe flaw allows an authenticated attacker to trigger a denial-of-service (DoS) condition by supplying specially crafted XML input.\nAffected products include IBM App Connect Enterprise 13.0.1.0 through 13.0.8.1, 12.0.1.0 through 12.0.12.28, and IBM Integration Bus for z/OS 10.1.0.0 through 10.1.0.7 Toolkit.\nThe risk implication is service unavailability, as the improper handling of XML entities can lead to resource exhaustion or process instability.\nSuccessful exploitation requires the attacker to be authenticated to the system. Once authenticated, the attacker can submit malicious XML payloads that force the application to consume excessive system resources, effectively causing the service to crash or become unresponsive to legitimate traffic.\nThis vulnerability highlights the necessity of strict XML input validation and the configuration of XML parsers to prevent common entity-based attacks.",
  "technicalDetails": "The vulnerability originates from inadequate sanitization and validation of XML entities during the parsing process within the affected IBM software products.\nXML entities, particularly those defined in Document Type Definitions (DTD), can be used to trigger complex processing or resource-heavy operations when the parser expands them.\nThe root cause is the failure of the XML processing engine to properly restrict or limit the expansion of these entities, which leads to a condition where the system attempts to process recursive or excessively large entity structures.\nThe attack flow begins with an authenticated user crafting a malicious XML payload containing crafted entity references or nested structures. This payload is transmitted to the vulnerable service component responsible for parsing XML data.\nUpon receiving the malicious XML, the affected component's parser attempts to expand the entities as part of its standard document processing routine.\nIf the XML document is structured to exploit the entity expansion mechanism (such as an XML External Entity or Billion Laughs-style attack), the parser may consume significant CPU cycles or memory allocation, exceeding the thresholds defined for the application's runtime environment.\nThis behavior forces the service into a state of resource exhaustion, resulting in a denial-of-service condition where the affected process terminates or becomes unresponsive to concurrent requests.\nThe vulnerability affects multiple versions of IBM App Connect Enterprise (13.0.x and 12.0.x) and IBM Integration Bus for z/OS (10.1.x).\nAuthentication is a prerequisite for exploitation, meaning the threat actor must already have access to the environment where they can submit XML payloads to the integration node or associated services.\nPost-exploitation impact is primarily limited to service disruption; the ability to cause a crash prevents the system from fulfilling its intended business logic, potentially stalling critical enterprise integration workflows.\nThere is no evidence suggesting this vulnerability facilitates arbitrary code execution; however, the resulting DoS condition remains a significant availability concern for high-availability environments."
}