Deserialization of Untrusted Data in Cisco Identity Services Engine (ISE) - CVE-2026-20211

 

Deserialization of Untrusted Data in Cisco Identity Services Engine (ISE) - CVE-2026-20211

Published: September 18, 2026


Vulnerability identifier: #VU150791
CSH Severity: Low
CVSS v4: 8.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-20211
CWE-ID: CWE-502
Exploitation vector: Remote access
Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a remote user to execute arbitrary code on the target system.

The vulnerability exists due to insecure deserialization of Java objects. A remote administrator can pass specially crafted data to the application and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.


Affected software

Cisco Identity Services Engine (ISE)

How to mitigate CVE-2026-20211

Install updates from vendor's website.

Cisco Identity Services Engine (ISE) - addressed in versions 3.1.0.518-Patch12, 3.2.0.542-Patch11, 3.3.0.430-Patch12, 3.4.0.608-Patch7, 3.5.0.527-Patch4

External References

Related Security Bulletins