Cisco Identity Services Engine Event Injection Vulnerability

published 2026-09-16 53 d ago modified 2026-09-28 42 d ago also EUVD-2026-81142

cvss: 5.3; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.4%; EPSS 0.4% chance of exploitation in 30 days, percentile 33%
public exploits: 0; none known

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.

Patch / fix

fixed in 2

cisco identity_services_engine 3.3.0
cisco identity_services_engine_passive_identity_connector 3.3.0

CISA SSVC

Exploitation: none
Automatable: yes
Technical impact: partial
Assessed: 52 d ago (2026-09-18)

Exploit prediction

0.39% chance of exploitation in the next 30 days, higher than 33% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	5.3	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

Affected products

Cisco Cisco Identity Services Engine Software
Cisco Cisco ISE Passive Identity Connector

Classification

Weakness

CWE-306 Missing Authentication for Critical Functionality

References

sec.cloudapps.cisco.com /security/center/content/CiscoSecurityAdvisory/cisco-sa-ise-multiauth-bypass-sgD2HbL4
vendor-advisory

Sources

CVE List CVE-2026-76439
NVD CVE-2026-76439

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary