Improper input validation in Cisco Identity Services Engine Software

CVE-2026-20237

As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco Identity Services Engine (ISE) and Cisco ISE Passive Identity Connector (ISE-PIC), engineering teams have conducted a comprehensive internal security review. This review resulted in a software hardening release that addresses multiple internally discovered vulnerabilities. The vulnerabilities tracked by CVE-2026-20237 are related to improper input validation issues that are grouped under the Common Weakness Enumeration (CWE) Pillar CWE-20.

Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)

CVSS v3 metric

CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-20237?
CVE-2026-20237 is a critical-severity vulnerability in Cisco Identity Services Engine Software, classified under Improper Input Validation. CVSS score: 9.1/10. Published 2026-09-16.
How severe is CVE-2026-20237?
Critical severity. CVSS v3 base score is 9.1 out of 10.