CVE-2026-76432 in Identity Services Engine Software
Summary
by MITRE • 09/16/2026
A vulnerability in the web-based management interface of Cisco ISE and Cisco ISE-PIC could allow an authenticated, remote attacker with administrative-level privileges to write arbitrary files on an affected device.
This vulnerability exists because the affected software does not properly validate directory traversal character sequences in a user-supplied file path during the upload process. An attacker could exploit this vulnerability by uploading a crafted file to the affected system. A successful exploit could allow the attacker to write files to an arbitrary location on the affected system.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 09/16/2026
The identified security flaw resides within the web-based management interface of Cisco Identity Services Engine (ISE) and its associated Platform Information Collector (PIC). This vulnerability specifically impacts systems where an authenticated user possesses administrative-level privileges, allowing for a remote attack vector that does not require physical access to the device. The core technical deficiency is rooted in improper input validation during file upload operations. Specifically, the software fails to adequately sanitize or validate directory traversal character sequences embedded within user-supplied file paths. This lack of rigorous checks permits an attacker to manipulate the intended destination path for uploaded files by injecting special characters that navigate up the directory structure, effectively bypassing the expected sandboxed or restricted directories designated for such operations.
From a technical perspective, this flaw is classified under CWE-22: Improper Limitation of a Pathname to a Restricted Directory. The mechanism of exploitation involves an attacker crafting a malicious file upload request where the filename or associated metadata contains sequences designed to traverse parent directories, typically represented by dot-dot-slash patterns in Unix-like systems or similar constructs in Windows environments. By successfully submitting this crafted payload through the administrative web interface, the attacker can force the system to write files outside of their intended scope. This capability fundamentally undermines the principle of least privilege and file isolation, as it allows for arbitrary file writes across the operating system's filesystem hierarchy rather than being confined to a specific application directory.
The operational impact of this vulnerability is severe due to the high level of access required by the attacker. Since exploitation requires administrative privileges on the ISE or PIC interface, an insider threat or an external actor who has compromised such credentials can leverage this flaw for significant system compromise. The ability to write files to arbitrary locations enables a variety of malicious activities beyond simple data leakage. An attacker could overwrite critical configuration files, inject backdoors into executable directories, or place scripts in startup paths to achieve persistence on the target device. This capability effectively grants the attacker full control over the underlying operating system, facilitating further lateral movement within the network and potentially leading to complete infrastructure compromise if ISE serves as a central authentication point for broader enterprise security policies.
In terms of threat modeling, this vulnerability aligns with MITRE ATT&CK techniques related to file manipulation and persistence. Specifically, it relates to T1505: Server Software Component, which covers the installation or modification of software components on servers, including web shells or configuration changes that allow for continued access. The attack vector is categorized as Network-based (T1078) with High Privileges (T1078.004), emphasizing the necessity of strong credential management and multi-factor authentication to mitigate the risk of unauthorized administrative access in the first place.
Mitigation strategies must focus on both immediate remediation and long-term security hardening. The primary defense is applying the vendor-provided software updates that address this input validation flaw, ensuring that directory traversal sequences are properly rejected or sanitized during file upload processes. Organizations should also enforce strict role-based access control (RBAC) to limit administrative privileges only to those users who absolutely require them, thereby reducing the attack surface for potential exploitation. Additionally, implementing network segmentation and monitoring tools can help detect anomalous file system activities resulting from successful exploits. Regular audits of user permissions and continuous patch management are essential components of a robust defense-in-depth strategy against such vulnerabilities in critical infrastructure components like Cisco ISE.