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CVE-2026-20306

CRITICAL 9.1 ALL-YEARS

Published 2026-09-16 · Last modified 2026-09-17 · cisco · NVD: Awaiting Analysis

A vulnerability in the REST API of Cisco ISE and ISE-PIC could allow an authenticated, remote attacker to perform command injection attacks on the underlying operating system and elevate privileges to root. To exploit this vulnerability, the attacker must have valid administrative credentials. This vulnerability is due to improper validation of user-supplied input. An attacker could exploit this vulnerability by sending crafted commands to the web-based management interface of an affected device. A successful exploit could allow the attacker to execute arbitrary code on the device and elevate privileges to root. In single-node deployments, successful exploitation of this vulnerability could cause the affected ISE node to become unavailable, resulting in a DoS condition. In that condition, endpoints that have not already authenticated would be unable to access the network until the node is restored.

ELEVATED IMPACT

Severe if exploited (CVSS 9.1), but no confirmed exploitation. Patch on a normal cadence.

Exploitation likelihood

1.4%chance of exploitation in 30 days · 71st percentile

○ In CISA KEV○ Public exploit / PoC◆ SSVC: exploitation none, automatable no

Impact if exploited

9.1CVSS 3.1 · CRITICAL · CNA

  • ConfidentialityHigh
  • IntegrityHigh
  • AvailabilityHigh

What an attacker needs

  • ✓Access: Reachable over the network — no local access needed
  • ⚠Privileges: Requires an admin / high-privilege account
  • ✓User interaction: No user interaction needed
  • ✓Complexity: No special conditions — reliably repeatable

✓ lowers the bar for an attacker · ⚠ raises it

Proof of concept & exploit code

No public exploit or proof-of-concept code is catalogued for this CVE (no ExploitDB, Nuclei, or CISA-KEV entry). It may still exist — search GitHub or check the references below.

Affected

Vendors Cisco

Products Cisco Identity Services Engine Software Cisco Ise Passive Identity Connector

Weakness (CWE)

  • CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')

CVSS vector

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

All CVSS metrics

  • CRITICAL 9.1 v3.1 · CNA Primary
    CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
  • CRITICAL 9.1 v3.1 · NVD Secondary
    CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

References

Technical & other

Sources: NVD · CVE.org · EPSS