Executive Summary

A critical vulnerability, CVE-2026-15435, has been identified in IBM App Connect Enterprise. This vulnerability allows an unauthenticated remote attacker to traverse directories and write arbitrary files on the system. The CVSS score for this vulnerability is 9.8, indicating a high severity level.

Technical Analysis

CVE-2026-15435 is a directory traversal vulnerability classified under CWE-22. The vulnerability exists in IBM App Connect Enterprise versions 12.0.1.0 through 12.0.12.27 and 13.0.1.0 through 13.0.7.2. An attacker can exploit this vulnerability by sending a specially crafted URL request containing "dot dot" sequences (/../) to write arbitrary files on the system.

How It Gets Exploited

An unauthenticated remote attacker on the same network can send a specially crafted URL request to the vulnerable IBM App Connect Enterprise instance. The request would contain "dot dot" sequences (/../) designed to traverse directories on the system. Upon receiving such a request, the vulnerable component fails to properly validate the input, allowing the attacker to write arbitrary files on the system. This could lead to a range of malicious activities, including but not limited to, achieving arbitrary code execution, data exfiltration, or privilege escalation.

Impact Assessment

The affected products are IBM App Connect Enterprise versions 12.0.1.0 through 12.0.12.27 and 13.0.1.0 through 13.0.7.2. An attacker exploiting this vulnerability could achieve high impact on confidentiality, integrity, and availability (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H). The CVSS score for this vulnerability is 9.8, indicating a critical severity level.

Recommended Actions

To mitigate this vulnerability, it is recommended to:
  • Update IBM App Connect Enterprise to version 12.0.12.28 or later for versions 12.0.1.0 through 12.0.12.27.
  • Update IBM App Connect Enterprise to version 13.0.7.3 or later for versions 13.0.1.0 through 13.0.7.2.
  • Implement network segmentation to restrict access to the vulnerable component.
  • Monitor for suspicious activity, such as unusual file modifications or requests containing "dot dot" sequences.

Sources

  • National Vulnerability Database (NVD) - https://nvd.nist.gov/vuln/detail/CVE-2026-15435
  • IBM Support Page - https://www.ibm.com/support/pages/node/7281896