Unauthenticated Remote Forged Posture Events in Cisco ISE Guest Portal
CVE-2026-76439 Published on September 16, 2026
Cisco Identity Services Engine Event Injection Vulnerability
A vulnerability in the endpoint posture status reporting functionality of the guest portal web application of Cisco ISE could allow an unauthenticated, remote attacker to submit forged posture status events into the endpoint posture pipeline.
This vulnerability is due to insufficient authentication on an internal interface that is exposed through the guest portal. An attacker could exploit this vulnerability by sending a crafted request to an affected system. A successful exploit could allow the attacker to manipulate the posture status on the affected system.
Vulnerability Analysis
CVE-2026-76439 can be exploited with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality, with no impact on integrity, and no impact on availability.
Weakness Type
Missing Authentication for Critical Function
The software does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources.
Products Associated with CVE-2026-76439
Want to know whenever a new CVE is published for Cisco Identity Services Engine Software? stack.watch will email you.
Affected Versions
Cisco Identity Services Engine Software:- Version 3.1.0 is affected.
- Version 3.1.0 p1 is affected.
- Version 3.1.0 p3 is affected.
- Version 3.1.0 p2 is affected.
- Version 3.2.0 is affected.
- Version 3.1.0 p4 is affected.
- Version 3.1.0 p5 is affected.
- Version 3.2.0 p1 is affected.
- Version 3.1.0 p6 is affected.
- Version 3.2.0 p2 is affected.
- Version 3.1.0 p7 is affected.
- Version 3.3.0 is affected.
- Version 3.2.0 p3 is affected.
- Version 3.2.0 p4 is affected.
- Version 3.1.0 p8 is affected.
- Version 3.2.0 p5 is affected.
- Version 3.2.0 p6 is affected.
- Version 3.1.0 p9 is affected.
- Version 3.3 Patch 2 is affected.
- Version 3.3 Patch 1 is affected.
- Version 3.3 Patch 3 is affected.
- Version 3.4.0 is affected.
- Version 3.2.0 p7 is affected.
- Version 3.3 Patch 4 is affected.
- Version 3.4 Patch 1 is affected.
- Version 3.1.0 p10 is affected.
- Version 3.3 Patch 5 is affected.
- Version 3.3 Patch 6 is affected.
- Version 3.4 Patch 2 is affected.
- Version 3.3 Patch 7 is affected.
- Version 3.4 Patch 3 is affected.
- Version 3.5.0 is affected.
- Version 3.4 Patch 4 is affected.
- Version 3.3 Patch 8 is affected.
- Version 3.2 Patch 8 is affected.
- Version 3.5 Patch 1 is affected.
- Version 3.3 Patch 9 is affected.
- Version 3.2 Patch 9 is affected.
- Version 3.4 Patch 5 is affected.
- Version 3.5 Patch 3 is affected.
- Version 3.5 Patch 2 is affected.
- Version 3.3 Patch 10 is affected.
- Version 3.3 Patch 11 is affected.
- Version 3.4 Patch 6 is affected.
- Version 3.2 Patch 10 is affected.
- Version 3.1.0 p72 is affected.
- Version 3.1.0 p11 is affected.
- Version 3.2.0 is affected.
- Version 3.1.0 is affected.
- Version 3.3.0 is affected.
- Version 3.4.0 is affected.
- Version 3.5.0 is affected.