CVE-2026-73786

Executive Summary

CVE-2026-73786 is an unauthenticated remote Denial-of-Service (DoS) vulnerability in the web-based management interface of "CPPM" (ClearPass Policy Manager), a network access control (NAC) / RADIUS authentication platform. The flaw is remotely exploitable over the network without authentication or user interaction and carries a CVSS v3.1 base score of 7.5 (HIGH), driven entirely by the Availability impact (A:H), with no Confidentiality or Integrity impact.

Affected organizations are those operating a CPPM server with a network-reachable management interface. Successful exploitation degrades performance and causes service instability, which — because ClearPass is an authentication and authorization control plane — can cascade into network access disruption for downstream devices and users. There is currently no public exploit code, no Nuclei template, no EPSS score, no CISA KEV listing, and no vendor patch evidence.

Technical Analysis

Vulnerability class and mechanism. The CNA description states that the vulnerability resides in the web-based management interface of CPPM and permits an unauthenticated remote attacker to conduct a DoS, resulting in instability and degraded performance of the server. This description maps to the resource-exhaustion family of flaws (CWE-400, Uncontrolled Resource Consumption, and its closely related denial-of-service variants). The mechanism is therefore best characterized at the class level as an availability-impacting flaw triggered through a management-interface request path that consumes a disproportionate amount of server resources relative to the cost of sending it — the defining asymmetry of an amplification/DoS condition.

Attack surface. The exposed surface is the CPPM management web interface. This is a distinct logical plane from the RADIUS/TACACS+/HTTPS enforcement services that ClearPass exposes to network devices; the CVE explicitly scopes the flaw to the management interface. An attacker must be able to reach that interface over the network (AV:N), needs no credentials (PR:N), and the request must succeed without any victim interaction (UI:N). The scope is unchanged (S:U), meaning the impact is assessed as confined to the vulnerable CPPM component rather than spilling into other security authorities.

Code-level detail. Insufficient technical detail is available. The provided NVD entry and CNA title contain no function names, class names, URL endpoints, parameter names, or file paths. No CWE was formally assigned in the data provided. Accordingly, this report does not speculate about specific handlers, endpoints, or parsing routines. The defensible characterization is: an unauthenticated, network-reachable, availability-only flaw in the CPPM management web interface with an unspecified resource-consumption trigger.

Why availability-only is still severe for a NAC. ClearPass Policy Manager is commonly the policy decision point for wired, wireless, and VPN access. If the management plane is degraded to the point of instability, administrative remediation, policy updates, certificate lifecycle operations, and observability all degrade simultaneously — at precisely the moment defenders need them. Even where enforcement services remain independently available, operational control of the platform is lost.

Exploitation Scenarios

No public PoC, exploit code, or Nuclei template exists for CVE-2026-73786. The attack chain below is described only at the vulnerability-class level as required, and does not assert any specific endpoint, parameter, or request structure.

1) Reconnaissance / target identification. The attacker enumerates internet- or intra-enterprise-reachable hosts serving the CPPM management web interface. Identification is typically by HTTP response title/banner or TLS certificate subject associated with the CPPM product. Presence of the management interface on an untrusted segment is the prerequisite condition.

2) Triggering the flaw class. Because the flaw is unauthenticated, the attacker does not need to complete a login flow. At the vulnerability-class level, the attacker sends crafted requests to the management interface designed to consume excessive server resources — the classic uncontrolled-resource-consumption pattern. Any claim about the exact request shape, parameter, or rate required would be speculation and is deliberately omitted.

3) Payload/execution method. There is no code execution, file drop, or credential theft in this vulnerability. The "payload" is the abusive request traffic itself. The attacker's objective is saturation: enough resource consumption (CPU, memory, worker/thread pool, connection table, or I/O — the exact resource is unspecified) that the management interface becomes unstable or unresponsive.

4) Post-exploitation impact. The attacker achieves degraded performance and instability of the vulnerable CPPM server. Downstream effects follow from CPPM's role: loss of administrative control of the NAC policy engine, potential interruption or degradation of authentication/authorization services dependent on the platform, and operator inability to triage or remediate during the incident. There is no confidentiality or integrity impact per the CVSS vector (C:N/I:N).

Threat-actor framing. DoS against an authentication control plane is attractive as a supporting action — degrading NAC while conducting other operations — and as a straightforward disruption/attention-denial play. No known campaigns or in-the-wild exploitation are documented for this CVE at the time of writing.

Impact Assessment

CVSS v3.1 decomposition (7.5 HIGH):

• AV:N — exploitable remotely across a network boundary.
• AC:L — no special conditions or race window required.
• PR:N — no authentication required; the highest-leverage factor here.
• UI:N — no victim action needed; no phishing or social element.
• S:U — impact assessed as confined to the vulnerable component.
• C:N / I:N — no data disclosure or data modification.
• A:H — the sole impact metric; complete loss of availability of the affected service.

Blast radius. The primary victim is the CPPM server's management interface. The secondary blast radius is organization-dependent and potentially large: any network, user, or device whose access depends on ClearPass policy decisions, plus the security team's ability to administer those decisions. Because the flaw is unauthenticated, the barrier to entry is low; because it is availability-only, the incident is operationally disruptive rather than a breach.

Business impact. Authentication-outage scenarios translate directly into help-desk load, access-control workarounds (and the compensating risk those introduce), and potential SLA breaches for network access. Regulatory impact is limited absent an accompanying confidentiality/integrity incident.

Detection Guidance

Detection for CVE-2026-73786 depends on identifying anomalous request volumes and resource-exhaustion patterns against the CPPM management interface. Because no technical indicators (paths, parameters, payloads) are published, rules below target behavioral signatures — request-rate anomalies, resource exhaustion, and service-health degradation — and should be tuned to each environment's observed baseline.

Sigma Rule

title: Potential CPPM Management Interface Denial-of-Service (CVE-2026-73786)
id: 8f2c1a44-7b6e-4d13-9c0a-cppm73786dos
status: experimental
description: Detects high-volume or anomalous web requests targeting the CPPM management interface consistent with an unauthenticated DoS attempt (CVE-2026-73786). Behavioral rule - no known payload signature exists.
references:
  - https://nvd.nist.gov/vuln/detail/CVE-2026-73786
author: Valters IT Threat Intelligence
date: 2026/01/01
logsource:
  category: webserver
  product: cppm
detection:
  selection_target:
    cs-uri-stem|contains:
      - '/tips/'
      - '/guest/'
      - '/api/'
  selection_status:
    sc-status:
      - 500
      - 502
      - 503
  timeframe: 5m
  condition: selection_target and selection_status | count() > 100 by src_ip
falsepositives:
  - Legitimate bulk administrative operations
  - Vulnerability scanners and synthetic monitoring
level: high
tags:
  - attack.t1499
  - cve.2026-73786

YARA Rule

rule CVE_2026_73786_CPPM_DoS_Behavioral
{
    meta:
        description = "Behavioral placeholder for CVE-2026-73786 CPPM management interface DoS. No payload signature is published; use for log/telemetry artifacts only."
        author = "Valters IT Threat Intelligence"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2026-73786"
        date = "2026-01-01"
        severity = "high"
    strings:
        $mgmt_a = "ClearPass" ascii nocase
        $mgmt_b = "CPPM" ascii nocase
        $err_a  = "503 Service Unavailable" ascii
        $err_b  = "502 Bad Gateway" ascii
        $dos_a  = "connection reset" ascii nocase
        $dos_b  = "worker timeout" ascii nocase
    condition:
        (any of ($mgmt_a, $mgmt_b)) and
        (any of ($err_a, $err_b)) and
        (any of ($dos_a, $dos_b))
}

Suricata IDS Rule

alert http any any -> any any (msg:"CVE-2026-73786 Possible CPPM Management Interface DoS Attempt"; flow:established,to_server; http.host; pcre:"/(?i)cppm|clearpass/"; http.uri; pcre:"/(?i)\/(tips|guest|api)\//"; threshold: type both, track by_src, count 100, seconds 60; classtype:attempted-dos; reference:cve,2026-73786; sid:202673786; rev:1;)

Elastic Detection

sequence by source.ip with maxspan=60s
  [http where http.response.status_code >= 500 and
   wildcard(http.request.path, "/tips/*", "/guest/*", "/api/*")]
  [http where http.response.status_code >= 500 and
   wildcard(http.request.path, "/tips/*", "/guest/*", "/api/*")]
  [http where http.response.status_code >= 500 and
   wildcard(http.request.path, "/tips/*", "/guest/*", "/api/*")]

Splunk SPL Query

index=web OR index=cppm sourcetype=access_combined OR sourcetype=cppm:web
| eval is_cppm=if(match(lower(host) OR lower(uri), "(?i)cppm|clearpass"), 1, 0)
| where is_cppm=1
| eval is_error=if(status>=500 AND status<=503, 1, 0)
| bin _time span=1m
| stats count AS total_reqs, sum(is_error) AS server_errors, dc(uri) AS distinct_uris BY _time, src_ip
| where server_errors > 50 AND total_reqs > 200
| sort - server_errors
| table _time, src_ip, total_reqs, server_errors, distinct_uris

Wazuh OSSEC Rule

<group name="web,cppm,attack,">
  <rule id="100737861" level="10" frequency="60" timeframe="60">
    <if_matched_sid>31151</if_matched_sid>
    <same_source_ip />
    <description>CVE-2026-73786: Possible CPPM management interface Denial-of-Service (repeated HTTP 5xx errors from single source)</description>
    <mitre>
      <id>T1499</id>
    </mitre>
    <group>denial_of_service,pci_dss_10.2.4,</group>
  </rule>

  <rule id="100737862" level="12">
    <if_sid>100737861</if_sid>
    <match>service unavailable|bad gateway|gateway timeout</match>
    <description>CVE-2026-73786: CPPM management service degradation consistent with DoS exploitation</description>
    <mitre>
      <id>T1499</id>
    </mitre>
  </rule>
</group>

Mitigation & Patch Guidance

Patch confidence: 0/4 — UNPATCHED. No vendor fix, fixed version, advisory, or workaround is present in any tracked source. AFFECTED_VERSION is empty, so version-based remediation scoping cannot be performed from this data alone. Treat all deployed CPPM instances as potentially affected until the vendor publishes a fixed release, and verify version applicability directly with the vendor.

1) Immediate mitigations

• Restrict network reachability to the CPPM management interface. Place it behind a management VLAN, jump host, or VPN, and enforce firewall/ACL rules so that only authorized administrative source IPs can reach it. This directly removes the AV:N / PR:N exposure path an unauthenticated external attacker would use.
• Do not expose the CPPM management interface to the public internet or to untrusted campus/guest segments.
• Enable rate limiting / connection limits at the reverse proxy or load balancer fronting the interface to blunt resource-exhaustion traffic.
• Ensure the enforcement (RADIUS/TACACS+) plane and the management plane are segmented so that load on one does not degrade the other, and that enforcement services are not dependent on management-plane availability.
• Enable and forward CPPM management web logs and application/health logs to the SIEM, and baseline normal request rates so anomalies are detectable.

2) Patch / upgrade steps

• No patched version is available. Monitor the vendor's security advisory channel for CPPM / ClearPass Policy Manager continuously and apply the fixed release immediately upon publication.
• Until a fix exists, maintain the compensating controls above and re-evaluate exposure each time the management interface is touched (upgrades, config changes, new remote-admin access grants).

3) Long-term hardening

• Adopt a zero-trust posture for all NAC control-plane management interfaces: no direct internet exposure, least-privilege administrative access, strong authentication (MFA) and full administrative audit logging.
• Implement continuous vulnerability monitoring and vendor-advisory ingestion for CPPM so that this CVE and future ones are actioned automatically.
• Build a documented DoS playbook that covers CPPM/mgmt-plane degradation: rate-limit, isolate affected host, fail over to secondary nodes if available, and preserve forensic logs.
• Where topology permits, deploy redundant CPPM nodes so that a single-node DoS does not cause a full authentication outage.

References

• NVD — CVE-2026-73786: https://nvd.nist.gov/vuln/detail/CVE-2026-73786 (primary source for this report; contains no CWE, no affected version range, no vendor advisory link)
• HPE Aruba Networking security advisories (CPPM / ClearPass Policy Manager) — check the vendor's advisory portal for a fix and affected-version matrix: https://www.arubanetworks.com/support-services/security-bulletins/ (no vendor advisory specific to CVE-2026-73786 was present in the provided data)
• CISA Known Exploited Vulnerabilities catalog — CVE-2026-73786 is not listed (verified: CISA KEV = NO): https://www.cisa.gov/known-exploited-vulnerabilities-catalog
• FIRST EPSS — not yet scored for this CVE at time of writing; no EPSS value should be assumed: https://www.first.org/epss/
• MITRE ATT&CK — T1499 Endpoint Denial of Service: https://attack.mitre.org/techniques/T1499/

Exploit-in-the-wild / campaign status: No public PoC (POC_STATUS: None), no Nuclei template, no exploit code, and no documented threat-actor campaigns are associated with CVE-2026-73786 in the provided data. No indicators of compromise are published.