CVE-2026-76439: Missing Auth (CVSS 5.3)

Description

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.

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CVSS v3.1 Score

5.3

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

Weakness Type (CWE)

CWE-306 Missing Authentication

References

Other References

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

Frequently Asked Questions

What is CVE-2026-76439? +

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. It has a CVSS v3.1 base score of 5.3 (MEDIUM).

How severe is CVE-2026-76439? +

CVE-2026-76439 has a CVSS v3.1 score of 5.3 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.

How do I check if I'm vulnerable to CVE-2026-76439? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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