Identity Services EngineApplication · Cisco
CVE-2026-20186
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedA 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 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.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceA command injection vulnerability in Cisco Identity Services Engine allows authenticated attackers with Read Only Admin privileges to execute arbitrary commands via crafted HTTP requests. The attacker gains user-level OS access and can escalate to root privileges. In single-node deployments, exploitation causes DoS, preventing unauthenticated endpoints from accessing the network.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
Identity Services EngineApplication
< 3.2.0= 3.2.0= 3.3.0= 3.4.0CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Changed
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify Cisco ISE versionLog into the Cisco ISE admin UI and navigate to Administration > System > Settings > Product Version, or run 'show version' via CLI to determine the installed software version.Affected if The installed version is any release prior to 3.2.0, or exactly 3.2.0, 3.3.0, or 3.4.0.
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Enumerate Read Only Admin accountsIn the Cisco ISE admin UI, go to Administration > Identity Management > Identities > Users, or query via CLI with 'show running-config | include user' to list all administrative accounts and their privilege levels.Affected if Any Read Only Admin accounts are present in the system.
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Review HTTP request logs for crafted payloadsIn Cisco ISE, access the operation logs (Administration > Logging > Audit Logs) and filter for HTTP requests from Read Only Admin sessions, looking for suspicious characters or patterns typical of command injection (such as semicolons, pipes, backticks, or $( ) in parameters).Affected if HTTP requests from Read Only Admin accounts contain suspicious command injection patterns.
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Check for unexpected command executionReview Cisco ISE system logs and OS-level audit logs for any commands executed under the 'ise' or 'admin' user accounts that were not initiated by Super Admin sessions.Affected if Commands were executed by non-Super Admin users or without corresponding Super Admin activity.
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Verify network accessibility of management interfaceConfirm whether the Cisco ISE admin web interface (port 443) is exposed to untrusted networks or the internet by reviewing firewall rules and interface bindings.Affected if The management interface is accessible from untrusted networks, increasing exposure to authenticated attackers.
You are affected if your Cisco ISE version falls within < 3.2.0, = 3.2.0, = 3.3.0, or = 3.4.0 and you have Read Only Admin accounts configured, as the vulnerability allows those accounts to inject commands via crafted HTTP requests.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped3.2.0
Apply the Cisco ISE security patch when available, or implement strict least-privilege controls on admin accounts and consider network segmentation to limit exposure to authenticated attackers.
ISE version 3.4.1 or later (or 3.5.0 if available)
- 1. Confirm current ISE version by navigating to Administration > System > Licensing > Software Version or using 'show version' in CLI
- 2. Schedule a maintenance window for the upgrade (ISE upgrades typically require downtime)
- 3. Backup the ISE configuration via Administration > System > Backup & Restore > Configuration Backup or 'application backup' CLI command
- 4. For single-node deployments, be aware that upgrade will cause temporary network access interruption for unauthenticated endpoints
- 5. Download the fixed ISE version (3.4.1 or later, or 3.5.0 if available) from Cisco.com software downloads
- 6. Perform the upgrade following Cisco ISE upgrade guide: navigate to Administration > System > Maintenance > Software Upgrade > Software Updates
- 7. Verify successful upgrade by confirming new version in 'show version' output
- 8. Validate critical services are operational: 'show application status ise'
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Identity Services Engine
Scoped from the published advisory
- Consultation4.0 h
- Implementation12.0 h
- Testing8.0 h
- Review / QA4.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $7,808.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-20186 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-20186 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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