Deserialization of Untrusted Data in Cisco Identity Services Engine (ISE) - CVE-2026-20307
Published: September 18, 2026
Vulnerability identifier: #VU150801
CSH Severity: Medium
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-20307
CWE-ID: CWE-502
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to insecure deserialization of a user-supplied Java byte stream. A remote user 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-2026-20307
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-Patch3