CVE-2026-17443 in App Connect Enterprise
Summary
by MITRE • 09/04/2026
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 could allow a remote authenticated attacker to obtain sensitive information due to an XML external entity (XXE) injection flaw.
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Analysis
by VulDB Data Team • 09/04/2026
The vulnerability identified in IBM App Connect Enterprise and IBM Integration Bus for z/OS represents a significant security risk stemming from improper handling of XML data inputs, specifically classified as an XML External Entity or XXE injection flaw. This type of vulnerability arises when an application processes untrusted XML input that includes references to external entities without proper validation or sanitization mechanisms in place. In the affected versions of IBM App Connect Enterprise ranging from 13.0.1.0 through 13.0.8.1, and version 12.0.1.0 through 12.0.12.28, as well as IBM Integration Bus for z/OS versions 10.1.0.0 through 10.1.0.7, the underlying XML parser allows an attacker to inject malicious entity definitions that can be resolved by the server during parsing operations. This flaw is particularly dangerous because it does not require administrative privileges or complex exploitation techniques beyond having valid authentication credentials and access to a service endpoint capable of processing XML payloads.
From a technical perspective, XXE vulnerabilities occur when developers fail to disable external entity resolution in their XML parsers or do not adequately restrict the types of entities that can be loaded. When an authenticated attacker submits a crafted XML document containing a reference to a local file on the server's filesystem or a remote resource controlled by the attacker, the parser may resolve this reference and include its contents within the parsed output. This mechanism effectively turns the application into a proxy for reading arbitrary files from the system where it is hosted. The impact of such an action can be severe, as sensitive configuration files, source code, database credentials stored in plaintext, or other confidential data residing on the server could be exfiltrated to the attacker's controlled location via HTTP requests triggered by the external entity resolution process.
The operational impact of this vulnerability extends beyond simple information disclosure. By leveraging XXE injection, an authenticated user can potentially map out the internal file system structure of the host machine, identify critical configuration paths, and extract secrets that could facilitate further attacks such as privilege escalation or lateral movement within the network infrastructure. Since IBM App Connect Enterprise serves as a middleware platform for integrating various applications and data sources across enterprises, compromising its integrity poses a risk to the broader ecosystem it supports. Attackers who gain access to sensitive integration configurations might manipulate message flows, intercept communications between systems, or disrupt business-critical processes that rely on accurate data transformation and routing provided by these IBM products.
This vulnerability aligns with Common Weakness Enumeration identifier CWE-611, which describes Improper Restriction of XML External Entity Reference. It also maps to the MITRE ATT&CK framework under techniques related to Collection via Client Side Injection or potentially Data from Local System depending on how the exfiltration is executed, specifically falling within tactics like Credential Access if sensitive files containing credentials are targeted. The requirement for authentication means that this vulnerability primarily affects environments where internal users have access to integration endpoints without sufficient role-based access controls or input validation layers implemented at the network perimeter or application level.
Mitigation strategies must focus on both immediate remediation and long-term architectural improvements. IBM has released patches addressing these specific version ranges, so applying the latest updates provided by IBM is the primary corrective action required for affected systems. Beyond patching, organizations should implement strict input validation policies that reject any XML content containing external entity declarations unless absolutely necessary for business logic. Developers integrating with App Connect Enterprise or Integration Bus should ensure that their own applications do not pass unsanitized user-controlled data into XML processing functions without employing secure coding practices such as disabling DTDs and external entities in the parser configuration where possible. Additionally, deploying Web Application Firewalls configured to detect XXE patterns can provide an additional layer of defense against exploitation attempts targeting these middleware components.