Identity Services Engine Passive Identity ConnectorApplication · Cisco
CVE-2026-20147
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 ISE and Cisco ISE-PIC 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 valid administrative 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 this vulnerability 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 confidenceCommand injection vulnerability in Cisco ISE and ISE-PIC allows authenticated remote attackers to execute arbitrary OS commands via crafted HTTP requests due to insufficient input validation. Successful exploitation provides user-level access with potential root privilege escalation.
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 Engine Passive Identity ConnectorApplication
< 3.1.0= 3.1.0= 3.2.0= 3.3.0= 3.4.0= 3.5.0
Identity Services EngineApplication
< 3.1.0= 3.1.0= 3.2.0= 3.3.0= 3.4.0= 3.5.0CVSS 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 the installed Cisco ISE product typeAccess the CLI via SSH or console and run the command to display system information, such as `show version` or `show product`, to determine if the system is Cisco ISE or Cisco ISE-PICAffected if The system is identified as Cisco ISE or Cisco ISE-PIC
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Determine the installed software versionRun the version display command from the CLI (for example, `show version`) and note the full version number displayedAffected if The installed version is < 3.1.0, = 3.1.0, = 3.2.0, = 3.2.1, = 3.3.0, = 3.4.0, or = 3.5.0 (all versions through 3.5.0 are affected)
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Verify the administrative web interface is accessibleCheck if TCP port 443 (default HTTPS admin port) or port 80 is open and listening on the ISE appliance using a port scanner or netstat commandAffected if The HTTP/HTTPS administrative interface is exposed and reachable on the network
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Confirm administrator authentication is enabledLog into the ISE CLI or check the admin access settings to verify that local or external administrator authentication is configured and activeAffected if Administrator accounts with valid credentials exist and can authenticate to the web interface
If the system runs Cisco ISE or ISE-PIC version 3.5.0 or earlier and has its administrative web interface accessible with active administrator accounts, the environment is potentially affected by this command injection vulnerability.
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 · scoped3.1.0
Apply Cisco's official patch/update for CVE-2026-20147 and restrict administrative access to trusted personnel until the fix is deployed.
Cisco ISE version 3.4.0 or later
- 1. Log in to the Cisco ISE administration interface with administrative credentials
- 2. Navigate to Administration > System > Software Updates > Software Images
- 3. Download Cisco ISE version 3.4.0 or later from the Cisco Software Download page
- 4. Create a backup of the current ISE configuration before proceeding
- 5. Schedule a maintenance window as exploitation causes DoS in single-node deployments
- 6. Upload the software image to the ISE node(s)
- 7. Install the upgrade following Cisco ISE upgrade procedure: Administration > System > Upgrade > Upgrade Wizard
- 8. Verify the upgrade was successful by logging into the ISE admin GUI
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Identity Services Engine Passive Identity Connector
Scoped from the published advisory
- Consultation6.0 h
- Implementation8.0 h
- Testing6.0 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 $6,816.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-20147 — 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-2026-20147 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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A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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