Cisco Identity Services Engine Software CVE-2026-20186

We need to produce a JSON with specific fields. The input: CVE-2026-20186, a Cisco ISE vulnerability. Description says: authenticated, remote attacker with Read Only Admin to execute arbitrary commands on OS. Insufficient input validation, crafted HTTP request, user-level access then elevate to root. In single-node deployments, DoS possible. CVSS 9.9 (AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H). CWE-77: Command Injection. EPSS 0.23% (46th percentile). KEV status not in input? Input does not mention KEV. Tags: Denial Of Service, Cisco, Command Injection, Cisco Identity Services Engine Software. SSVC: Exploitation: none, Automatable: no, Technical Impact: total. ENISA EUVD lists many affected versions. CPE: cpe:2.3:a:cisco:cisco_identity_services_engine_software:*:*:*:*:*:*:*:*. References: Cisco advisory, NVD, vuldb. No mention of POC or KEV in the multi-source intelligence. SSVC says exploitation: none and automatable: no (so no active exploitation, not automatable). So the exploitation status is "no public exploit identified at time of analysis". No KEV listing.

We must synthesize all data. product_name: "Cisco Identity Services Engine Software" but maybe just "Cisco ISE"? The description says "Cisco Identity Services Engine (ISE)". So "Cisco Identity Services Engine" but too long? "Cisco ISE" might be recognized. "Cisco Identity Services Engine" is primary. I'll use "Cisco ISE" as product_name (1-3 words). "Cisco ISE" is okay (2 words). I'll use "Cisco ISE". But I can also say "Cisco Identity Services Engine Software". Three words: "Cisco ISE Software"? "Cisco ISE" is clear.

Summary: Not copy description. Start with impact verb. Example: "Command injection in Cisco ISE allows authenticated remote attacker with Read-Only Admin privileges to achieve OS command execution and privilege escalation to root, leading to total compromise and potential denial of service." Use EPSS, KEV? No KEV, EPSS low (0.23%), so not actively exploited. So: "A command injection vulnerability in Cisco Identity Services Engine (ISE) allows an authenticated attacker with Read-Only Admin privileges to execute arbitrary commands on the underlying OS via crafted HTTP requests, potentially escalating to root. Successful exploitation can lead to full device compromise and, in single-node deployments, a denial-of-service condition. Cisco has released a patch." No active exploitation. I'll incorporate EPSS: low exploitation probability. So: "Command injection in Cisco Identity Services Engine (ISE) allows an authenticated remote attacker with Read-Only Admin credentials to execute arbitrary commands on the underlying operating system via crafted HTTP requests, leading to full compromise with root access and, in single-node deployments, denial of service. Although the CVSS score is 9.9 (critical), EPSS indicates low exploitation probability (0.23%) and no active exploitation has been observed." That's good.

technical_context: Explain underlying tech, CWE-77 (Command Injection). Cisco ISE is a network access control policy engine. The vulnerability is command injection due to insufficient input validation. CPE indicates software versions. Reference CWE-77. So: "Cisco Identity Services Engine is a security policy management platform that controls network access. This vulnerability is a command injection (CWE-77) arising from insufficient validation of user input processed by the ISE web interface. The attacker can inject arbitrary commands that are executed on the underlying Linux-based operating system. Affected software versions include multiple patches of Cisco ISE 3.1, 3.2, 3.3, and 3.4 as listed in ENISA EUVD." I'll mention CPE.

risk_assessment: Use CVSS vector, EPSS, SSVC, KEV (none), POC (none). Compare signals: CVSS 9.9 Critical, but PR:L (read-only admin), so authentication is needed; attack complexity low, scope changed, so high impact. EPSS 0.23% is low, percentile 46% (so below median). SSVC: exploitation none, automatable no, so not currently being exploited, and not easily automated. So real-world risk is moderate: requires authenticated access with at least Read-Only Admin, which is not trivial, but if compromised, full control. So: "CVSS 9.9 indicates a critical severity due to network vector, low attack complexity, low privileges, and scope change leading to high impacts. However, exploitation requires an attacker to have Read-Only Admin privileges (PR:L), which limits the pool of potential attackers to those who can obtain such credentials. EPSS score of 0.23% (46th percentile) suggests low likelihood of widespread exploitation in the wild. SSVC analysis shows no current exploitation and not automatable, further reducing the immediate urgency. Although the impact is total compromise, the need for authenticated access to the management interface lowers the real-world risk, though organizations with exposed admin interfaces or weak credential hygiene face higher risk." I need to note conflicting or missing data: no active exploitation, patch available. No conflicting signals.

affected_products: List versions from EUVD enumeration. "Cisco Identity Services Engine Software versions 3.1.0 through 3.4 Patch 3 are affected. Specifically, multiple patch levels of 3.1, 3.2, 3.3, and 3.4 as listed by ENISA EUVD are vulnerable. The Cisco security advisory (cisco-sa-ise-rce-4fverepv) provides full details and fixed releases." I'll reference advisory URL.

remediation: "Cisco has released software updates to address this vulnerability; upgrades to the latest patched versions are recommended. Refer to the Cisco advisory cisco-sa-ise-rce-4fverepv for specific fixed versions (e.g., 3.1.0 Patch 10 or later, 3.2.0 Patch 7 or later, 3.3 Patch 7 or later, 3.4 Patch 3 or later). As a workaround, restrict network access to the ISE management interface to trusted IPs only, and enforce strong credential policies to prevent unauthorized read-only admin access. However, these are compensating controls; applying the vendor patch is the definitive solution." Since the vulnerability requires authenticated access, restricting admin interface access can help.

exploit_scenario: "An attacker who has obtained Read-Only Admin credentials (e.g., through phishing or credential reuse) could leverage the command injection via crafted HTTP request to achieve arbitrary command execution with user-level OS access, then elevate to root to take full control of the ISE node." So 2-3 sentences.

exploitation_conditions: Extract concrete prerequisites: Must have at least Read-Only Admin credentials (authenticated). Attack vector is network, but exploitation requires sending crafted HTTP request to the management interface. So specific condition: "The attacker must have valid credentials with at least Read-Only Admin privileges on the Cisco ISE device’s management interface. No configuration changes are required; the vulnerability exists in the input validation of a web application component. Exploitation is limited by the need for authenticated access to the administrative web interface, making it inaccessible to unauthenticated external attackers unless credentials are obtained." Also mention that single-node deployments extra DoS condition? Not a condition for exploitation, but impact. So: "Exploitation requires valid credentials with Read-Only Admin role on the ISE management web interface, which is typically restricted to network administrators. There is no indication that default configurations or public-facing deployments without authentication are vulnerable; however, if the admin interface is exposed to the internet or accessible without multi-factor authentication, the attack surface increases." Avoid generic phrases. So: "Requires authenticated access with at least Read-Only Admin credentials on the Cisco ISE administrative HTTP interface. No other special conditions—the flaw is present in default configurations as long as the attacker can interact with the web application." That's specific.

attack_chain: Use phases. Steps: Obtain Read-Only Admin credentials (recon/delivery) → Send crafted HTTP request to ISE web interface → Exploit command injection vulnerability → Execute arbitrary commands as user-level OS account → Elevate privileges to root → Achieve full compromise or denial of service. Short steps: "Obtain Read-Only Admin credentials" → "Send crafted HTTP request to ISE management web interface" → "Trigger command injection via insufficient input validation" → "Execute commands as unprivileged OS user" → "Elevate privileges to root" → "Full node compromise or single-node DoS". That's 6 steps.

confidence_notes: "Cisco has confirmed the vulnerability and released a security advisory with patches. Affected versions are listed by ENISA. No active exploitation has been reported; CISA KEV does not include this CVE, and SSVC indicates exploitation: none and automatable: no. The EPSS score is 0.23%, indicating low likelihood of exploitation. The CVSS vector and description are consistent. Missing: proof of concept code is not publicly available at this time." But we don't know about POC; can say "No public exploit code has been identified at time of analysis." So: "Cisco advisory confirms the vulnerability and patch availability. No active exploitation has been observed (not in CISA KEV, SSVC exploitation: none). EPSS low. Affected versions are confirmed via EUVD and vendor advisory. No public proof-of-concept code has been released. The CVSS vector aligns with the description." That's fine.

prevalence: Cisco ISE is a widely used network access control product in enterprise environments. So prevalence: "high". Justification: "Cisco ISE is a widely deployed enterprise access control solution." So prevalence_basis: "widely deployed enterprise access control solution". Good.

assessed_cvss_vector: My own independent CVSS 3.1 vector. I need to adjust? I can use: AV:N (network, HTTP request), AC:L (no special complexity, just crafted request), PR:L (requires read-only admin), UI:N (no user interaction beyond the attack request), S:C (scope change, OS commands executed on underlying OS from the application component), C:H/I:H/A:H (full compromise). So replicating the given vector. I'll output "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H". That's identical. I need to justify: "Requires authenticated access (PR:L) but no user interaction and no complexity; scope change leads to full impact." So rationale: "Network vector with low complexity, low privileges (Read-Only Admin), and scope change results in total system compromise." That's good.

assessed_cvss40_vector: Convert to CVSS 4.0 base vector. For base, we need AV, AC, AT, PR, UI, VC, VI, VA, SC, SI, SA. Attack Vector: Network (N). Attack Complexity: Low (L). Attack Requirements: None (N) — since no specific requirement, so AT:N. Privileges Required: Low (L). User Interaction: None (N). Vulnerable System Confidentiality: High (H) (commands executed on OS give access to data). Integrity: High (H). Availability: High (H). Subsequent System: None (N) for all, because it's the same system? Actually scope change from application to OS, but in CVSS 4.0, the Vulnerable System (the application web interface) is the first. The impact on the OS is considered a subsequent system? The vulnerable component is the web application, the subsequent system is the OS. So SC, SI, SA should reflect impact on the OS: High because full compromise. So "SC:H/SI:H/SA:H". But the CVSS 4.0 base vector uses VC/VI/VA for the vulnerable component's CIA, and SC/SI/SA for the subsequent system. So the vulnerable system is the web application itself: maybe not directly impacted? But the vulnerability is in the web app, and its exploitation leads to OS commands, so the web app's integrity might be compromised, but the impact is on the OS. In CVSS 3.1, scope changed, so the impacted component is the underlying OS (as subsequent system). For CVSS 4.0, we need to assign CIA to both components. The vulnerable component (the web app) might not suffer direct confidentiality/integrity/availability impact; it is used to execute code on a subsequent system. So VC/VI/VA could be N/N/N? But typical mapping: The attack results in execution of commands on the OS, so the vulnerable component (web app) might just be the vector, not directly impacted. But in CVSS 4.0, when scope changes, the vulnerable component gets some score from the subsequent. So I'll set VC:N, VI:N, VA:N (no direct impact on web app) and SC:H, SI:H, SA:H (full impact on OS). But that seems odd. Many assessments map S:C/C:H to SC:H in CVSS 4.