CVE-2026-76433 in Identity Services Engine Software
Summary
by MITRE • 09/16/2026
A vulnerability in the client provisioning download feature of Cisco ISE and Cisco ISE-PIC could allow an unauthenticated, remote attacker to access protected files on an affected device.
This vulnerability is due to insufficient validation of directory traversal character sequences in a user-supplied path when the software processes provisioning resource requests. An attacker could exploit this vulnerability by sending a crafted request to the provisioning download service. A successful exploit could allow the attacker to access protected files without authentication, potentially exposing sensitive information.
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Analysis
by VulDB Data Team • 09/16/2026
The identified security flaw resides within the client provisioning download functionality of Cisco Identity Services Engine and its associated Platform Integration Component. This component is designed to facilitate the automated deployment and configuration management for network devices by serving specific resource files required during the onboarding process. The vulnerability stems from a fundamental failure in input validation, specifically regarding how the software handles directory traversal character sequences embedded within user-supplied path parameters. When an attacker constructs a malicious request targeting the provisioning download service, they can inject special characters such as dot-dot-slash sequences to manipulate the file system navigation logic. Because the application does not adequately sanitize or restrict these inputs, it fails to confine the access scope to the intended directory structure, thereby allowing the traversal of parent directories beyond the authorized boundaries.
From a technical perspective, this represents a classic path traversal vulnerability where the lack of strict canonicalization allows an unauthenticated remote attacker to bypass authentication mechanisms entirely. The operational impact is significant as it grants unauthorized parties read-only access to protected files stored on the affected device. These files may contain sensitive configuration data, cryptographic keys, or internal system information that should remain inaccessible without proper credentials. By exploiting this flaw, an adversary can extract critical intelligence about the network infrastructure, potentially using this information to plan further attacks against more vulnerable systems within the environment. The ability to access these resources remotely and without authentication lowers the barrier for exploitation significantly, making it a high-risk issue for organizations relying on Cisco ISE for identity management and policy enforcement.
In terms of industry standard classifications, this vulnerability aligns with CWE-22 Improper Limitation of a Pathname to a Restricted Directory which describes flaws where software does not properly neutralize special elements within file paths that could cause unintended directory traversal. Furthermore, the exploitation technique corresponds to ATT&CK tactic T1083 File and Directory Discovery as well as T1530 Data from Cloud or On-Premises Systems since it involves enumerating and accessing files on a remote system without authorization. The lack of authentication requirement places this in the context of unauthenticated access vectors which are particularly dangerous due to their ease of exploitation by automated tools and script kiddies alike.
To mitigate this risk, organizations should ensure that all Cisco ISE and PIC components are updated to versions where this input validation issue has been resolved. If immediate patching is not feasible, network segmentation strategies can be employed to restrict access to the provisioning download service ports from untrusted networks or external internet sources. Additionally, implementing strict web application firewall rules that detect and block common directory traversal patterns in HTTP requests can provide a layer of defense-in-depth. Regular auditing of file system permissions and ensuring that sensitive configuration files are stored with appropriate operating system-level restrictions further reduces the potential impact should an exploitation attempt occur. Continuous monitoring for anomalous access patterns to provisioning endpoints is also recommended to detect any attempted or successful abuse of this vulnerability in real-time.