CVE-2026-76428: Cisco ISE SQL Injection Vulnerability

CVE-2026-76428 Overview

CVE-2026-76428 is a SQL injection vulnerability in the REST APIs of Cisco Identity Services Engine (ISE) and Cisco ISE Passive Identity Connector (ISE-PIC). An authenticated remote attacker with valid administrative credentials can inject SQL statements into affected API parameters. Successful exploitation allows the attacker to read information from the session database. The flaw is tracked under CWE-89: Improper Neutralization of Special Elements used in an SQL Command.

Critical Impact
Authenticated administrators can extract sensitive information from the Cisco ISE session database by crafting API requests containing SQL payloads in vulnerable parameters.

Affected Products

Cisco Identity Services Engine (ISE)
Cisco ISE Passive Identity Connector (ISE-PIC)
REST API components of Cisco ISE and ISE-PIC

Discovery Timeline

2026-09-16 - CVE-2026-76428 published to the National Vulnerability Database
2026-09-16 - Last updated in NVD database

Technical Details for CVE-2026-76428

Vulnerability Analysis

CVE-2026-76428 affects the REST API layer of Cisco ISE and ISE-PIC. The APIs process attacker-controlled parameters and concatenate them directly into SQL clauses without parameterization. This allows crafted input to alter the intended structure of database queries executed against the session database.

The vulnerability requires authentication with valid administrative credentials, which limits the attacker population but does not eliminate risk. Compromised administrator accounts, insider threats, and lateral movement scenarios can all lead to exploitation. Confidentiality is the primary concern, as successful exploits expose session data that may include authentication records and endpoint context.

Root Cause

The root cause is unsafe SQL query construction. Certain REST API endpoint parameters are appended to SQL statements as strings rather than bound as parameters through prepared statements. This design pattern is the canonical trigger for [CWE-89] SQL injection defects and permits input to break out of the intended value context and inject additional SQL syntax.

Attack Vector

An authenticated administrator sends a crafted HTTP request to a vulnerable REST API endpoint on the ISE or ISE-PIC management interface. The request contains SQL fragments embedded within an affected parameter. The backend concatenates the parameter into a query targeting the session database and returns data influenced by the injected clause. Because the attack is network-based, any host with reachability to the ISE administrative API and valid credentials can attempt exploitation.

See the Cisco Security Advisory - ISE Multi for vendor-specific technical details and the list of affected endpoints.

Detection Methods for CVE-2026-76428

Indicators of Compromise

REST API requests to Cisco ISE or ISE-PIC containing SQL metacharacters such as single quotes, UNION, SELECT, --, or ; within parameter values.
Unexpected administrative API activity originating from unusual source IP addresses or outside normal maintenance windows.
Anomalous read volumes or query latency against the ISE session database.

Detection Strategies

Inspect ISE administrative API access logs for parameter values containing SQL keywords or encoded injection payloads.
Correlate administrator authentication events with subsequent REST API calls to identify credential misuse or compromised accounts.
Deploy a web application firewall or API gateway in front of the ISE management interface with SQL injection signatures tuned for REST traffic.

Monitoring Recommendations

Forward Cisco ISE audit and REST API logs to a centralized SIEM for retention and correlation.
Alert on administrative logins from new geolocations, new user agents, or outside change windows.
Baseline normal REST API parameter patterns and alert on deviations that include SQL syntax.

How to Mitigate CVE-2026-76428

Immediate Actions Required

Review the Cisco Security Advisory - ISE Multi and apply the fixed software release identified for your deployment.
Restrict access to the ISE and ISE-PIC administrative interfaces to a dedicated management network and jump hosts.
Rotate administrative credentials and enforce multi-factor authentication for all ISE administrator accounts.
Audit administrator account inventory and remove unused or over-privileged accounts.

Patch Information

Cisco has published a security advisory addressing this vulnerability. Refer to the Cisco Security Advisory - ISE Multi for the list of fixed releases and upgrade guidance for Cisco ISE and ISE-PIC. Cisco has not published workarounds, so upgrading to a fixed release is the definitive remediation.

Workarounds

No official workarounds have been published by Cisco; upgrade to a fixed release.
Limit REST API exposure by placing ISE administrative interfaces behind network segmentation and access control lists.
Apply the principle of least privilege to administrative role assignments to reduce the number of accounts that can reach vulnerable endpoints.

bash

# Example: restrict access to the Cisco ISE administrative interface
# using an upstream ACL on the management network
access-list ISE_ADMIN_MGMT permit tcp host 10.10.10.5 host 10.20.30.40 eq 443
access-list ISE_ADMIN_MGMT permit tcp host 10.10.10.6 host 10.20.30.40 eq 443
access-list ISE_ADMIN_MGMT deny   tcp any host 10.20.30.40 eq 443 log