CVE-2026-79796

Executive Summary

CVE-2026-79796 is a critical (CVSS 9.8) authentication bypass vulnerability in the affected interface of ClearPass Policy Manager. An unauthenticated remote attacker can circumvent existing authentication controls and gain unauthorized access to the affected system. Successful exploitation grants full confidentiality, integrity, and availability impact (C:H/I:H/A:H) without requiring privileges or user interaction, making it a high-priority target for network-facing deployments.

Technical Analysis

The NVD description states that "vulnerabilities" (plural) have been identified in the affected interface of ClearPass Policy Manager that could allow an unauthenticated remote attacker to circumvent existing authentication controls. The exact affected interface, the specific authentication mechanism, and the underlying code-level flaw are not disclosed in the available data. No CWE identifier was provided by the vendor or NVD, and no affected version range was published.

Based on the vulnerability class — authentication bypass via an exposed network interface — the flaw most plausibly resides in how the affected interface validates or enforces authentication state before granting access to protected functionality. In authentication-bypass classes, this typically manifests as one of: (a) an endpoint that fails to validate a session or token, (b) a logic flaw where an authentication check is performed but its failure result is not enforced, or (c) an alternate code path (e.g., a debug, API, or administrative endpoint) that does not invoke the normal authentication control. Because the NVD text does not specify which of these applies, the precise mechanism cannot be confirmed.

The attack surface is network-accessible: the CVSS vector AV:N confirms the vulnerable interface is reachable over the network with no adjacent or local access requirement. The vector PR:N confirms no prior authentication is needed, and UI:N confirms no victim interaction is required — the attacker can trigger the flaw directly.

No public PoC, exploit code, or Nuclei template exists for this CVE. The attack chain described below is therefore inferred from the vulnerability class (unauthenticated authentication bypass over a network interface) and must not be read as confirmation of specific implementation details.

Exploitation Scenarios

No public PoC available; attack chain is inferred from vulnerability class. No specific function names, endpoints, API paths, or parameters are available from the source data, so the following is a class-level description.

1. Reconnaissance and target identification — An attacker identifies internet- or network-exposed ClearPass Policy Manager instances, for example via Shodan searches for the product's login page title or HTML markers, or by scanning for the network services that expose the affected interface. No authentication or prior foothold is required.

2. Triggering the flaw — Because the flaw is an authentication bypass (PR:N, AV:N), the attacker sends a crafted request directly to the affected interface without valid credentials. The vulnerability class implies that the interface fails to enforce its authentication control for the crafted request, allowing the attacker to reach protected functionality that should require login. The exact request structure is not disclosed.

3. Payload/execution method — At the vulnerability-class level, exploitation consists of crafting the request that satisfies (or evades) the flawed authentication check, rather than delivering a memory-corruption payload or uploading code. No specific HTTP method, path, header, or parameter is identified in the available data and none is fabricated here.

4. Post-exploitation impact — Per the CVSS vector, successful exploitation yields high confidentiality, integrity, and availability impact (C:H/I:H/A:H). In context, ClearPass is a network access control (NAC) and policy platform, so unauthorized access to the affected system could expose policy configuration, authentication data, and the ability to alter access-control decisions for connected network devices. The full scope of post-exploitation capability depends on what the affected interface permits once authentication is bypassed, which is not specified in the source data.

Impact Assessment

CVSS 3.1 base score is 9.8 (Critical) with vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

• Attack Vector (N): remotely exploitable across a network.
• Attack Complexity (L): no specialized conditions or race windows are indicated.
• Privileges Required (N): no authentication needed — the flaw itself bypasses authentication.
• User Interaction (N): no victim action required.
• Scope (U): impact is confined to the vulnerable component.
• Confidentiality/Integrity/Availability (H/H/H): total loss of each.

Business impact: ClearPass Policy Manager is a network access control platform; unauthorized access to it can undermine the authentication and authorization decisions that govern an entire network. An attacker with access to the affected system could potentially view or modify policy data and authentication-related configuration, affecting downstream network devices and users that rely on the platform for access decisions. Blast radius extends to any network segment, device, or identity that ClearPass governs. EPSS has not yet been scored by FIRST.org, so no exploitation-likelihood estimate is available. CVE-2026-79796 is not in CISA KEV, and no exploit code or PoC is publicly available at the time of writing.

Detection Guidance

The rules below are behavioral/class-level detections for unauthenticated access to a protected interface. Because no concrete endpoint, parameter, or payload is disclosed, these rules target anomalies surrounding unauthenticated requests to ClearPass and authentication-bypass patterns generally; they require tuning to the deployment's normal traffic baselines. Placeholder values (paths, hostnames) must be adjusted to the environment.

Sigma Rule

title: ClearPass Policy Manager Unauthenticated Access Attempt (CVE-2026-79796)
id: 8f2c1a90-4b7e-4d3a-9f10-7c5e2a6b4d31
status: experimental
description: Detects unauthenticated requests reaching protected ClearPass Policy Manager interface paths, consistent with an authentication bypass attempt.
references:
  - https://nvd.nist.gov/vuln/detail/CVE-2026-79796
author: valtersit.com
date: 2026/01/01
logsource:
  category: webserver
detection:
  selection_product:
    cs-uri-stem|contains:
      - '/clearpass'
      - '/policy-manager'
      - '/tips'
  selection_unauthenticated:
    sc-status:
      - 200
      - 302
    cs-username: '-'
  filter_known_scanners:
    cs-user-agent|contains:
      - 'HealthCheck'
      - 'uptime-monitor'
  condition: selection_product and selection_unauthenticated and not filter_known_scanners
falsepositives:
  - Legitimate login and pre-authentication pages that return 200 before authentication
  - Authorized vulnerability scanners
level: high
tags:
  - attack.initial_access
  - attack.t1190

YARA Rule

rule CVE_2026_79796_ClearPass_AuthBypass
{
    meta:
        description = "Behavioral indicator rule for CVE-2026-79796 ClearPass Policy Manager authentication bypass; matches request artifacts associated with unauthenticated access to protected ClearPass interfaces."
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2026-79796"
        author = "valtersit.com"
        date = "2026-01-01"
        severity = "critical"

    strings:
        $p1 = "/clearpass" ascii nocase
        $p2 = "ClearPass Policy Manager" ascii nocase
        $a1 = "Authorization: Bearer" ascii nocase
        $a2 = "X-Forwarded-For" ascii nocase
        $s1 = "bypass" ascii nocase
        $s2 = "admin" ascii nocase

    condition:
        uint16(0) == 0x4854 and
        (any of ($p1, $p2)) and
        (any of ($a1, $a2)) and
        (any of ($s1, $s2))
}

Suricata IDS Rule

alert http any any -> any any (msg:"CVE-2026-79796 ClearPass Policy Manager Unauthenticated Access Attempt"; flow:established,to_server; http.uri; content:"/clearpass"; nocase; http.header; content:"Authorization"; nocase; negate; classtype:attempted-admin; reference:cve,2026-79796; reference:url,nvd.nist.gov/vuln/detail/CVE-2026-79796; sid:202679796; rev:1;)

Elastic Detection

sequence by source.ip with maxspan=30s
  [network where network.protocol == "http" and url.path : ("*clearpass*" or "*policy-manager*")]
  [http where http.response.status_code in (200, 302) and user.name == null]

Splunk SPL Query

index=web OR index=proxy sourcetype=access_combined
| eval path=lower(uri_path)
| where match(path,"(?i)(clearpass|policy-manager|/tips)")
| where status IN (200,302)
| where isnull(user) OR user="-" OR user=""
| stats count min(_time) as first_seen max(_time) as last_seen values(status) as statuses by src_ip, uri_path, user_agent
| where count >= 5
| sort - count

Wazuh OSSEC Rule

<group name="web,clearpass,">
  <rule id="100796" level="12">
    <if_sid>31100</if_sid>
    <url>clearpass|policy-manager|/tips</url>
    <status>200|302</status>
    <description>CVE-2026-79796: Possible unauthenticated access attempt against ClearPass Policy Manager interface</description>
    <mitre>
      <id>T1190</id>
    </mitre>
    <group>authentication_bypass,</group>
  </rule>
</group>

Mitigation & Patch Guidance

Patch confidence: 0/4 (UNPATCHED — no patch evidence from any tracked source).

1. Immediate mitigations

• Reduce exposure: restrict network access to the affected ClearPass interface to trusted management networks and administrative source IPs. Do not expose the interface directly to the internet.
• Apply network-layer controls: place the affected interface behind firewall rules, ACLs, or a reverse proxy that enforces authentication and limits reachable paths.
• Monitor and rate-limit: enable verbose logging on the ClearPass interface and alert on unauthenticated requests reaching protected paths (see Detection Guidance). Rate-limit or block anomalous source IPs.
• Disable or segment any non-essential interfaces or services associated with ClearPass Policy Manager that are not required for operation.

2. Patch/upgrade steps

• No vendor fix or patched version is currently identified by tracked sources. Monitor the vendor (Aruba/HPE) security advisory channels and the NVD entry for CVE-2026-79796 for an official patch and affected-version matrix.
• When a patch is released: inventory all ClearPass Policy Manager instances and version levels, test the fix in a staging environment, then upgrade all production instances. Verify the applied version against the vendor's fixed-version list.

3. Long-term hardening

• Enforce defense-in-depth so that a single authentication flaw does not grant full access: require mutual TLS or certificate-based client authentication for management interfaces where supported.
• Segment the NAC infrastructure so ClearPass is not reachable from general user or guest network segments.
• Maintain an asset inventory and version-tracking process to rapidly identify and remediate vulnerable instances when advisories are published.
• Integrate vendor advisories and NVD into an automated vulnerability management workflow with defined SLAs for critical (CVSS >= 9.0) findings.

References

• NVD — CVE-2026-79796: https://nvd.nist.gov/vuln/detail/CVE-2026-79796
• CISA Known Exploited Vulnerabilities Catalog: https://www.cisa.gov/known-exploited-vulnerabilities-catalog (CVE-2026-79796 not currently listed)
• FIRST EPSS: https://www.first.org/epss (CVE-2026-79796 not yet scored at time of writing)
• Vendor security advisories (Aruba/HPE): https://www.arubanetworks.com/support-services/security-bulletins/ (monitor for advisory referencing CVE-2026-79796)
• MITRE ATT&CK T1190 — Exploit Public-Facing Application: https://attack.mitre.org/techniques/T1190/

No public exploit code, PoC, Nuclei template, or in-the-wild exploitation evidence for CVE-2026-79796 was identified in the available data. No threat actor campaign has been attributed to this CVE to date.