Cyber Resilience

CVE-2026-20186

RCE in Cisco Identity Services Engine ≤ 3.2.0

Published
15 April 2026
Modified
29 June 2026
Patch / advisory
CVSS Score v3.1 9.9
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
EPSS Score 0.063 93th percentile
Risk Priority 75 floored blend · peak EPSS

Summary

CVE-2026-20186 is a critical-severity Command Injection (CWE-77) vulnerability in Cisco Identity Services Engine. Its CVSS base score is 9.9 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Command and Scripting Interpreter (T1059); ranked in the top 7% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2026-20186 is a command injection vulnerability (CWE-77) in Cisco Identity Services Engine (ISE) that enables an authenticated, remote attacker to execute arbitrary commands on the underlying operating system of an affected device. The flaw arises from insufficient validation of user-supplied input, earning a CVSS v3.1 base score of 9.9 (AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H).

An attacker with at least Read Only Admin credentials can exploit the vulnerability by sending a crafted HTTP request to an affected ISE device. Successful exploitation provides user-level access to the operating system, allowing subsequent privilege escalation to root privileges. In single-node ISE deployments, exploitation can also trigger a denial-of-service condition, making the node unavailable and preventing unauthenticated endpoints from accessing the network until restoration.

The official Cisco Security Advisory at https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ise-rce-4fverepv provides further details on affected versions, exploitation conditions, and recommended mitigations or patches.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

A vulnerability in Cisco Identity Services Engine (ISE) could allow an authenticated, remote attacker to execute arbitrary commands on the underlying operating system of an affected device. To exploit this vulnerability, the attacker must have at least Read Only Admin…

more

credentials. This vulnerability is due to insufficient validation of user-supplied input. An attacker could exploit this vulnerability by sending a crafted HTTP request to an affected device. A successful exploit could allow the attacker to obtain user-level access to the underlying operating system and then elevate privileges to root. In single-node ISE deployments, successful exploitation of these vulnerabilities could cause the affected ISE node to become unavailable, resulting in a denial of service (DoS) condition. In that condition, endpoints that have not already authenticated would be unable to access the network until the node is restored.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1059 Command and Scripting Interpreter Execution
Adversaries may abuse command and script interpreters to execute commands, scripts, or binaries.
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1059.001 PowerShell Execution
Adversaries may abuse PowerShell commands and scripts for execution.
T1059.003 Windows Command Shell Execution
Adversaries may abuse the Windows command shell for execution.
T1059.004 Unix Shell Execution
Adversaries may abuse Unix shell commands and scripts for execution.
T1059.008 Network Device CLI Execution
Adversaries may abuse scripting or built-in command line interpreters (CLI) on network devices to execute malicious command and payloads.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-20153Same product: Cisco Identity Services Engine
CVE-2023-20122Same product: Cisco Identity Services Engine
CVE-2023-20170Same product: Cisco Identity Services Engine
CVE-2023-20152Same product: Cisco Identity Services Engine
CVE-2026-20147Same product: Cisco Identity Services Engine
CVE-2023-20022Same product: Cisco Identity Services Engine
CVE-2023-20175Same product: Cisco Identity Services Engine
CVE-2023-20021Same product: Cisco Identity Services Engine
CVE-2023-20023Same product: Cisco Identity Services Engine
CVE-2024-20469Same product: Cisco Identity Services Engine

Affected Assets

cisco
identity services engine
3.2.0, 3.3.0, 3.4.0 · ≤ 3.2.0

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V1.2.3
  • V1.2.5
  • V1.2.8
  • V1.2.9

Mitigating Controls (NIST 800-53 r5) AI

Developer testing and evaluation can discover command-construction flaws before deployment.

Input validation directly stops construction of commands from untrusted data containing special elements.

Secure engineering principles include proper neutralization and safe command construction practices.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly require input validation and neutralization that prevent command injection.

DE.CM-09 partial match
prevents

Runtime monitoring of software and data can detect anomalous command execution resulting from injection.

ID.RA-01 partial match
prevents

Identifying recorded vulnerabilities enables remediation of command-injection flaws before exploitation.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

prevents

Secure coding standards require proper escaping and parameterization of commands, directly eliminating CWE-77.

finds

Security testing in development catches command-injection vulnerabilities before release.

prevents

Secure development life cycle mandates input validation and command construction practices that directly prevent command injection.

prevents

Application security requirements explicitly call for controls against injection flaws including command injection.

prevents

Secure architecture principles reduce the attack surface but do not prescribe the specific neutralization techniques needed.

none

Environment separation limits the blast radius of an exploited command injection but does not prevent the flaw itself.

References