CVE-2026-78026

Executive Summary

CVE-2026-78026 is an authorization bypass through user-controlled key (CWE-639) in Dell Secure Connect Gateway (SCG) Policy Manager versions prior to 5.34.00.16. A low-privileged, remotely authenticated attacker can manipulate a user-controlled key used in an authorization decision, causing the application to grant access to resources or operations that should be restricted, resulting in elevation of privileges. The CVSS 3.1 base score is 4.3, reflecting limited confidentiality impact only; integrity and availability are not impacted, and the affected scope remains unchanged.

Technical Analysis

The vulnerability class is CWE-639, Authorization Bypass Through User-Controlled Key, also commonly referred to as IDOR (Insecure Direct Object Reference) in its object-access form or, more broadly, authorization bypass via attacker-influenced key material. The root cause is that the application makes an authorization decision based on a key (identifier, object reference, role/tenant selector, or similar token) that is supplied or modifiable by the user, without validating that the authenticated principal is actually entitled to the referenced resource or action.

In the CVE-2026-78026 case, the affected product is Dell Secure Connect Gateway (SCG) Policy Manager, a component used to manage connectivity and policy between Dell infrastructure and Dell support/backend services. The advisory states only that a "low privileged attacker with remote access could potentially exploit this vulnerability, leading to Elevation of privileges." No specific endpoint, parameter name, API path, or function name is disclosed in the NVD description, so the precise request that carries the attacker-controlled key cannot be stated without fabricating details. The mechanistic description must therefore remain at the class level:

1. A legitimate, authenticated low-privilege session exists. The attacker already holds valid credentials for a low-privilege account, satisfying the PR:L (privileges required: low) precondition in the CVSS vector.
2. The web/API layer accepts a user-controllable key — for example an object identifier, resource reference, or role/scope selector — as part of a request, and uses that key to look up the target resource or to evaluate whether the operation is permitted.
3. Because the authorization check trusts the user-supplied key rather than deriving the key from the authenticated session and validating ownership/entitlement against it, the check can be satisfied by a low-privilege principal while the operation actually executes against a higher-privilege resource or action.
4. The result is a horizontal-to-vertical privilege transition: an operation normally reserved for an administrative role is performed by the low-privilege caller.

The CVSS subscores clarify the technical scope. AV:N (network) confirms the attack is remotely reachable; AC:L (low complexity) indicates no special conditions, race windows, or high-skill preconditions beyond a valid low-privilege account; PR:L confirms the attacker is authenticated but not privileged; UI:N confirms no victim interaction is required — the attacker triggers the bypass directly. S:U (unchanged) means the compromised component can affect only its own security authority, not components beyond its security scope. C:L indicates the attacker can read or access some restricted data, consistent with an authorization bypass that exposes protected resources; I:N and A:N indicate the described impact does not include modification or destruction of data, nor denial of service. This is important: per the published vector, the exploited access is primarily a confidentiality breach through unauthorized read or use of restricted functionality, not data tampering or service outage. The advisory's phrase "Elevation of privileges" describes the authorization-state change (the low-privilege user obtains access it should not have), while the CVSS impact triad scopes the realized effect to limited confidentiality.

Because no proof-of-concept, exploit code, or Nuclei template is publicly tracked, and no OSV package data or affected-version list is available, the technical detail here is derived entirely from the CWE class and the vendor's advisory text. Any specificity beyond the class mechanism would be speculation.

Exploitation Scenarios

The following chain is inferred from the vulnerability class (CWE-639) and the advisory text. There is no public PoC; the sequence below is a class-level model, not a reproduction of a known exploit.

1. Reconnaissance and target identification. The attacker identifies an internet- or network-reachable Dell Secure Connect Gateway (SCG) Policy Manager instance running a version prior to 5.34.00.16. The attacker also needs at least one valid low-privilege account on that instance (PR:L). Discovery uses normal application interaction: enumerating reachable web/API interfaces, observing identifiers present in requests and responses, and mapping which operations are exposed.

2. Triggering the flaw class. The attacker authenticates with the low-privilege account and issues requests in which the key that drives the authorization decision is attacker-controlled. In CWE-639 this classically means supplying or substituting an object identifier, resource reference, or scope/role selector so that the request points at a resource or action belonging to a higher-privileged context. The authorization logic should reject this, but because it trusts the user-supplied key, it processes the request under the attacker's assumption of entitlement.

3. Payload/execution method (class level). No memory-corruption or code-injection payload is required. The "payload" is the crafted request itself, carrying the manipulated key. Exploitation is a logic/authorization flaw, so the execution method is simply issuing the request over the network to the vulnerable interface with the attacker-controlled key in place. No specific endpoint, parameter, or identifier name is disclosed in the available data, so none is asserted here.

4. Post-exploitation impact. Per the CVSS vector, the realized effect is limited confidentiality (C:L) with no integrity or availability impact: the attacker gains unauthorized access to restricted data or functionality via the elevation of privileges described by the vendor. Blast radius is bounded by S:U — the impact stays within the SCG Policy Manager component's own security authority. The meaningful consequence is that a low-privilege user effectively crosses a privilege boundary within the appliance's policy-management functionality.

Impact Assessment

Business impact centers on the erosion of the authorization boundary in a policy-management component for Dell infrastructure connectivity. The primary risk is unauthorized access to data that should be restricted to higher-privileged roles (C:L). Because the CVSS vector specifies I:N and A:N, the described impact does not include data modification or service disruption, which limits the blast radius relative to a tamper- or DoS-capable flaw.

Affected systems are Dell Secure Connect Gateway (SCG) Policy Manager deployments at versions prior to 5.34.00.16. The unchanged scope (S:U) means the vulnerability's security authority does not extend beyond this component, so the issue should not be treated as a cross-system compromise vector based on the provided data. The PR:L precondition means the attacker must first obtain a valid low-privilege account; this raises the bar versus an unauthenticated flaw and reduces the exposed population to instances where an attacker can obtain such an account (stolen credentials, a legitimately provisioned low-privilege user, etc.). The 4.3 base score is consistent with a moderate-severity access-control defect rather than a critical one, but the "elevation of privileges" wording means organizations should not dismiss it: authorization bypasses in management-plane software can serve as a stepping stone if chained with other weaknesses or used to harvest sensitive configuration/telemetry. No EPSS score is currently published by FIRST.org, and there is no CISA KEV listing, no known exploit code, and no known in-the-wild activity, so the assessed exploitation likelihood based on public evidence is currently low.

Detection Guidance

Because no public PoC identifies the exact request shape, the rules below target the generic behavior of an authenticated low-privilege principal successfully invoking higher-privileged functionality — the observable footprint of a CWE-639 authorization bypass — rather than a known payload string.

Sigma Rule

title: Potential Authorization Bypass via User-Controlled Key in Dell Secure Connect Gateway
id: 8f2c1a4e-7b6d-4c9a-b3e1-0d5f9a2c6e77
status: experimental
description: Detects authenticated access to privileged SCG Policy Manager functionality by low-privileged users, consistent with CWE-639 authorization bypass (CVE-2026-78026).
references:
  - https://nvd.nist.gov/vuln/detail/CVE-2026-78026
author: valtersit.com
date: 2026-01-01
logsource:
  product: webserver
  service: access
detection:
  selection_path:
    cs-uri-stem|contains:
      - '/policy'
      - '/admin'
      - '/api/'
  selection_status:
    sc-status: 200
  selection_identity:
    cs-username|exists: true
  filter_privileged:
    cs-username|endswith:
      - 'admin'
      - 'svc-'
  condition: selection_path and selection_status and selection_identity and not filter_privileged
falsepositives:
  - Legitimate low-privilege users accessing their own authorized endpoints
level: medium
tags:
  - attack.t1068
  - cve.2026-78026

YARA Rule

rule CVE_2026_78026_SCG_PolicyManager_AuthzBypass
{
    meta:
        description = "Hunts logs or captures referencing Dell Secure Connect Gateway Policy Manager versions prior to 5.34.00.16 and CWE-639 authorization bypass artifacts"
        author = "valtersit.com"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2026-78026"
        cve = "CVE-2026-78026"
        date = "2026-01-01"

    strings:
        $prod1 = "Secure Connect Gateway" nocase ascii wide
        $prod2 = "SCG Policy Manager" nocase ascii wide
        $cwe   = "CWE-639" nocase ascii wide
        $vuln  = "Authorization Bypass Through User-Controlled Key" nocase ascii wide
        $ver   = /5\.3[0-3]\.[0-9]{2}\.[0-9]{2}/ ascii

    condition:
        (uint16(0) == 0x5A4D) or (any of ($prod1, $prod2))
        and any of ($prod1, $prod2, $cwe, $vuln)
}

Suricata IDS Rule

alert http any any -> any any (msg:"CVE-2026-78026 Potential Dell SCG Policy Manager Authorization Bypass (CWE-639)"; flow:established,to_server; http.method; content:"GET"; http.uri; content:"/policy"; http.uri; content:"id="; http.header; content:"Authorization"; nocase; threshold:type both, track by_src, count 10, seconds 60; classtype:attempted-user; reference:cve,2026-78026; reference:url,nvd.nist.gov/vuln/detail/CVE-2026-78026; sid:202678026; rev:1;)

Elastic Detection

sequence by user.name with maxspan=60s
  [ authentication where event.outcome == "success" ]
  [ network where url.path : ("*policy*" or "*admin*" or "*api/*") and
      http.response.status_code == 200 and
      not user.name : ("*admin*" or "svc-*") ]

Splunk SPL Query

index=web OR index=proxy sourcetype=access_combined
| eval user=coalesce(cs_username, user, "")
| where user!="" AND NOT match(user, "(?i)admin|svc-")
| where match(uri_path, "(?i)/policy|/admin|/api/") AND status=200
| stats count AS privileged_hits values(uri_path) AS paths by src_ip user
| where privileged_hits >= 5
| sort - privileged_hits

Wazuh OSSEC Rule

<group name="web,access,cve-2026-78026,">
  <rule id="2026780" level="6">
    <decoded_as>web-accesslog</decoded_as>
    <regex type="pcre2">"\s2\d\d\s</regex>
    <description>Web request to protected SCG Policy Manager path returned success (possible CWE-639 authz bypass, CVE-2026-78026)</description>
  </rule>

  <rule id="2026781" level="10" frequency="5" timeframe="120">
    <if_matched_sid>2026780</if_matched_sid>
    <description>CVE-2026-78026: repeated successful access to privileged SCG Policy Manager endpoints</description>
    <mitre>
      <id>T1068</id>
    </mitre>
  </rule>
</group>

Mitigation & Patch Guidance

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

1. Immediate mitigations

• Because the vendor advisory states versions prior to 5.34.00.16 are affected, upgrade to 5.34.00.16 or later as the primary remediation path; treat that version as the vendor-indicated fixed baseline.
• Restrict network reachability of the SCG Policy Manager management interface to trusted management networks only. The AV:N vector means exposure should be minimized; removing internet exposure reduces the candidate attack surface to internal actors.
• Enforce least privilege on accounts that can authenticate to SCG Policy Manager, and audit which low-privilege accounts exist. The PR:L precondition means shrinking the low-privilege account population directly reduces exposure.
• Where the product permits, enforce strong authentication (MFA) and unique per-user credentials to make unauthorized use of a low-privilege account harder.
• Monitor and alert on low-privilege accounts invoking privileged functionality (see Detection Guidance) as a compensating detective control.

2. Patch/upgrade steps

• Obtain the fixed release (5.34.00.16 or later) only through Dell's official support channels. Verify the version after upgrade and confirm the advisory's fixed-version number matches the deployed build.
• If an authoritative Dell security advisory for this CVE is available, follow its specific upgrade and validation instructions; no workaround is documented in the provided data.
• Because patch confidence is 0/4 (no patch evidence from any tracked source), do not assume an available patch without confirming the fixed build from Dell directly.

3. Long-term hardening

• Institute server-side authorization that derives the authorization key from the authenticated session and validates entitlement against the referenced resource on every request; never trust user-supplied identifiers for access-control decisions (the CWE-639 remediation principle).
• Add automated IDOR/authorization-bypass testing (object reference fuzzing with multiple privilege levels) to the security test suite so this class is caught pre-deployment.
• Maintain an asset inventory of SCG deployments and subscribe to Dell security advisories so future fixes are applied promptly.
• Apply defense-in-depth: network segmentation, centralized logging of management-plane access, and periodic review of privileged-role assignments.

References

• NVD — CVE-2026-78026: https://nvd.nist.gov/vuln/detail/CVE-2026-78026
• CWE-639: Authorization Bypass Through User-Controlled Key: https://cwe.mitre.org/data/definitions/639.html
• CWE-566: Authorization Bypass Through User-Controlled SQL Primary Key (related class): https://cwe.mitre.org/data/definitions/566.html
• Dell Secure Connect Gateway (SCG) product and security documentation — consult Dell's official support portal for the advisory corresponding to CVE-2026-78026 and the 5.34.00.16 fixed build.
• MITRE ATT&CK T1068 — Exploitation for Privilege Escalation: https://attack.mitre.org/techniques/T1068/
• CISA Known Exploited Vulnerabilities Catalog (checked; CVE-2026-78026 is NOT listed as of this report): https://www.cisa.gov/known-exploited-vulnerabilities-catalog

Threat actor and exploit-in-the-wild note: No public proof-of-concept, exploit code, Nuclei template, or CISA KEV entry is associated with CVE-2026-78026 at the time of writing. No known threat actor campaign has been attributed. EPSS has not yet been scored by FIRST.org.