CVE-2026-20306: Cisco Identity Services Engine Software · OS Command Injection
Affects Cisco Identity Services Engine SoftwareSource CVE Database V5
Not known to be exploited · CVSS 9.1 Critical.
Data as of 31 Oct 2026, 20:20 UTC
- EPSS
- 1.5% chance of exploitation in 30 days – higher than 75% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 16 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 31 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| CiscoCisco Identity Services Engine Software | Affected
| Fixed in– |
| CiscoCisco ISE Passive Identity Connector | Affected
| Fixed in– |
Description
CVE-2026-20306 is a critical OS command injection vulnerability in the REST API of Cisco Identity Services Engine (ISE) version 3.4.0. An authenticated attacker with administrative credentials can exploit this flaw by sending crafted commands to the web management interface, leading to arbitrary code execution with root privileges. Exploitation in single-node deployments may cause a denial-of-service condition, making the ISE node unavailable and preventing unauthenticated endpoints from accessing the network.