CVE-2026-76426 Overview
CVE-2026-76426 is a SQL injection vulnerability in the REST API of Cisco Identity Services Engine (ISE) and Cisco ISE Passive Identity Connector (ISE-PIC). The flaw stems from insufficient validation of specific request parameters that are concatenated into SQL statements executed against the monitoring database [CWE-89]. An authenticated attacker with valid administrative credentials can send crafted API requests to read data from the monitoring database. Exploitation does not require user interaction and can be performed over the network.
Critical Impact
A remote attacker holding administrative credentials can extract sensitive information from the ISE monitoring database through crafted REST API requests.
Affected Products
- Cisco Identity Services Engine (ISE)
- Cisco ISE Passive Identity Connector (ISE-PIC)
- Refer to the Cisco Security Advisory for the exact fixed release trains
Discovery Timeline
- 2026-09-16 - CVE-2026-76426 published to NVD
- 2026-09-17 - Last updated in NVD database
Technical Details for CVE-2026-76426
Vulnerability Analysis
The vulnerability resides in one or more REST API endpoints exposed by Cisco ISE and ISE-PIC. Specific request parameters are passed directly into SQL statements without adequate sanitization or parameterization. An authenticated attacker can inject SQL syntax through these parameters and alter the intent of queries executed against the monitoring database.
Successful exploitation permits confidentiality-impacting reads from the monitoring database, which stores authentication, authorization, accounting, and posture assessment records. The attacker must already possess valid administrative credentials, which restricts exploitation to insiders or attackers who have compromised administrator accounts.
Root Cause
The root cause is improper neutralization of special elements used in an SQL command [CWE-89]. User-controlled input flows from a REST API parameter into a dynamically constructed SQL query without prepared statements or strict allow-list validation. This lets the attacker append or alter SQL clauses processed by the monitoring database.
Attack Vector
The attack vector is network-based over the ISE administrative REST API. An attacker authenticates with valid administrator credentials, then submits a crafted HTTP request containing SQL fragments within a vulnerable parameter. The injected SQL executes against the monitoring database and returns data through the API response or observable behavior. No user interaction is required, and the scope of impact remains within the ISE instance.
No public proof-of-concept exploit or in-the-wild exploitation has been reported for CVE-2026-76426 at the time of publication. See the Cisco Security Advisory: ISE Multi Vulnerability for technical details.
Detection Methods for CVE-2026-76426
Indicators of Compromise
- REST API requests from administrator accounts containing SQL metacharacters such as single quotes, --, UNION, SELECT, or ; in parameter values.
- Unusually large or slow REST API responses to administrative endpoints, suggesting bulk data extraction from the monitoring database.
- Administrator API sessions originating from unexpected source IP addresses or at anomalous times.
Detection Strategies
- Enable and centralize ISE administrative and REST API audit logs, then alert on parameter values that contain SQL injection patterns.
- Baseline normal REST API usage per administrator account and flag deviations in endpoint diversity, request volume, or response size.
- Correlate ISE monitoring database query patterns with the originating API activity to identify unexpected read operations.
Monitoring Recommendations
- Forward ISE syslog, admin audit, and API access logs to a SIEM or data lake for retention and correlation.
- Monitor administrator account authentication events for credential misuse, including logins from new geolocations or hosts.
- Alert on failed authorization attempts against REST API endpoints that may indicate reconnaissance preceding exploitation.
How to Mitigate CVE-2026-76426
Immediate Actions Required
- Apply the fixed Cisco ISE and ISE-PIC releases identified in the Cisco Security Advisory: ISE Multi Vulnerability.
- Rotate administrative credentials and enforce multi-factor authentication for all ISE administrator accounts.
- Restrict management and REST API access to a dedicated administrative network segment using ACLs and firewall rules.
- Review recent administrator API activity for signs of parameter tampering or bulk data reads.
Patch Information
Cisco has published fixed software releases in the security advisory cisco-sa-ise-multi-hrP9jQSQ. Consult the advisory for the specific patched versions applicable to your deployment and follow Cisco's upgrade guidance. There are no vendor-documented workarounds that fully eliminate the vulnerability; patching is the recommended remediation.
Workarounds
- Limit REST API exposure to a hardened jump host or bastion accessible only to authorized administrators.
- Enforce least-privilege administrative roles so that fewer accounts hold credentials capable of reaching vulnerable API endpoints.
- Increase logging verbosity on ISE administrative interfaces until patching is complete to improve incident visibility.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.