CVE-2026-76423

CRITICAL CVSS 10.0 PoC Available
Published: 2026-09-16
Modified: 2026-09-17
Enriched via mock
Tenable Plugin

Checking the public Tenable catalog…

AI Threat Summary

CVE-2026-76423 is a critical vulnerability with a CVSS score of 10.0 affecting the target software. Authentication can be bypassed allowing unauthenticated access. Threat hunters should monitor for exploit attempts and apply vendor patches immediately.

Description

A vulnerability in the REST API of Cisco ISE and Cisco ISE-PIC could allow an unauthenticated, remote attacker to gain administrative access to an affected device. This vulnerability is due to the REST API web service being exposed with insufficient authorization checks. An attacker could exploit this vulnerability by sending a crafted HTTP request to the exposed REST API port. A successful exploit could allow the attacker to read and modify ISE configuration and identity data with administrative privileges.

Attack Chain
1
Reconnaissance

Attacker identifies authentication endpoint and tests for bypass conditions

2
Initial Access

Attacker exploits CVE-2026-76423 authentication flaw to gain unauthorized access without valid credentials

3
Discovery

Attacker enumerates accessible resources, users, and configurations

4
Collection

Attacker exfiltrates sensitive data accessible without proper authorization

MITRE ATT&CK Techniques
T1078 Valid Accounts
Initial Access

Authentication bypass grants attacker access as legitimate user

T1548 Abuse Elevation Control Mechanism
Privilege Escalation

Bypassed auth may grant elevated or admin-level permissions

Indicators of Compromise
Type Value Description
user_agent Mozilla/5.0 (compatible; exploit/1.0) Generic exploit scanner user agent pattern
url /api/vuln-endpoint?payload=<malicious> Exploit attempt against application endpoint — monitor access logs for anomalous params
Remediation
1. Apply vendor-supplied security patches immediately. 2. If patches are unavailable, apply recommended mitigations from the vendor advisory. 3. Enable WAF rules or IDS signatures to detect exploitation attempts. 4. Monitor logs for indicators of compromise listed above. 5. Implement network segmentation to limit blast radius if exploitation occurs. 6. Subscribe to vendor security advisories for this product.
Quick Facts
CVE ID CVE-2026-76423
CVSS Score 10.0
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:L
Published 2026-09-16
Exploited No
CISA KEV No
PoC Available
References
External Resources
NVD Entry BleepingComputer The Hacker News