CVE-2026-76689

Executive Summary

CVE-2026-76689 is a stack-based buffer overflow (CWE-121) in the configuration processing logic of Aruba Networks EdgeConnect SD-WAN Orchestrator. An authenticated remote attacker holding administrative privileges can supply specially crafted configuration data to trigger the overflow. Successful exploitation can result in remote code execution with root privileges or a denial of service via system crash.

Technical Analysis

The vulnerability resides in the configuration processing logic of the affected component. According to the NVD description, malformed input is improperly processed when configuration data is parsed. The specific flaw class is a stack-based buffer overflow (CWE-121), meaning that input data is written into a fixed-size stack buffer without adequate bounds validation, allowing the write to exceed the allocated buffer boundary.

The attack surface is the configuration ingestion path exposed by the EdgeConnect SD-WAN Orchestrator. Because the exploit requires administrative privileges (PR:H in the CVSS vector), the vulnerable code path is reachable only after authentication and authorization as an administrator. The CVSS vector (AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H) indicates the attack is network-reachable, requires no user interaction, and — if successfully exploited — yields high impact to confidentiality, integrity, and availability. Note that the Scope value is Unchanged (S:U), meaning the impact is confined to the vulnerable component's security authority.

Specific function names, file paths, API endpoints, and parameter names are not disclosed in the available description. The vulnerability is best characterized at the class level: a stack buffer overflow during configuration data parsing. No public proof-of-concept, exploit code, or Nuclei template was observed at the time of reporting, and the EPSS score is 0.00852 (56.6th percentile), reflecting low near-term exploitation probability relative to the broader CVE population.

Exploitation Scenarios

No public PoC is available; the attack chain below is inferred from the vulnerability class and the stated preconditions.

1. Reconnaissance/target identification: The attacker identifies an internet- or internally exposed Aruba EdgeConnect SD-WAN Orchestrator instance. Access to the administrative interface is required, and administrative credentials must be obtained (e.g., through prior compromise, credential reuse, or weak credential policy). Because PR:H is required, this CVE is most realistically a post-authentication escalation primitive rather than an initial-access vector on its own.

2. Triggering the flaw class: The attacker, authenticated as an administrator, submits specially crafted configuration data to the orchestrator's configuration processing logic. The malformed input exceeds the bounds of a fixed-size stack buffer during parsing, corrupting adjacent stack memory (return addresses, saved frame pointers, or local variables).

3. Payload/execution method (class-level): In a classic stack-based buffer overflow, the attacker crafts input to overwrite the saved return address (or a function pointer) so that control flow is redirected to attacker-controlled data placed on the stack or elsewhere in memory. Because the process context is root, successful redirection yields code execution as root. Alternatively, an uncontrolled crash results in denial of service.

4. Post-exploitation impact: With root-level code execution on the orchestrator, the attacker could manipulate SD-WAN policy, pivot into managed edge devices, exfiltrate configuration and topology data, or disable orchestration entirely (DoS via crash). Insufficient technical detail is available to describe exact payload constraints (e.g., mitigations such as ASLR/stack canaries) or offset values.

Impact Assessment

The CVSS 3.1 base score is 7.2 (High). The AV:N/AC:L combination means the vulnerable configuration path is network reachable and requires no special attack conditions beyond valid admin credentials. PR:H and UI:N indicate the attacker must already hold administrative privileges but needs no victim interaction. The C/I/A subscores are all High (C:H/I:H/A:H), reflecting potential total loss of confidentiality, integrity, and availability of the orchestrator — including its managed SD-WAN fabric — if exploited.

Business impact includes: loss of centralized SD-WAN management control, potential configuration tampering across the managed estate, exfiltration of network topology and policy data, and availability loss from crashes. Blast radius is significant because the orchestrator is a high-value management-plane asset; compromise or destabilization can cascade to dependent edge devices. Scope is Unchanged, so impact is bounded to the component and its authority. KEV status is NO, indicating no confirmed in-the-wild exploitation as tracked.

Detection Guidance

Sigma Rule

title: Aruba EdgeConnect SD-WAN Orchestrator Config Buffer Overflow Attempt (CVE-2026-76689)
id: 7c3f1a2e-9b44-4e21-8a7d-0f1e2d3c4b5a
status: experimental
description: Detects oversized or malformed configuration uploads targeting Aruba EdgeConnect SD-WAN Orchestrator configuration processing logic.
author: Threat Intelligence
date: 2026/01/01
logsource:
  category: webserver
  product: aruba
detection:
  selection_method:
    cs-method:
      - POST
      - PUT
  selection_uri:
    cs-uri-stem|contains:
      - 'config'
      - 'orchestrator'
  selection_size:
    sc-bytes|gte: 8000
  condition: selection_method and selection_uri and selection_size
falsepositives:
  - Legitimate large configuration pushes
level: medium
tags:
  - attack.t1190
  - cve.2026.76689

YARA Rule

rule CVE_2026_76689_Aruba_EdgeConnect_Config_Overflow
{
    meta:
        description = "Detects oversized configuration payloads associated with stack-based buffer overflow in Aruba EdgeConnect SD-WAN Orchestrator configuration processing"
        author = "Threat Intelligence"
        date = "2026-01-01"
        reference = "CVE-2026-76689"
        cve = "CVE-2026-76689"

    strings:
        $cfg1 = "config" ascii nocase
        $cfg2 = "orchestrator" ascii nocase
        $pattern1 = { 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 }
        $pattern2 = { 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 }

    condition:
        (any of ($cfg*)) and (any of ($pattern*))
}

Suricata IDS Rule

alert http any any -> any any (msg:"CVE-2026-76689 Aruba EdgeConnect SD-WAN Orchestrator Config Buffer Overflow Attempt"; flow:established,to_server; http.method; content:"POST"; http.uri; content:"config"; nocase; dsize:>8000; reference:cve,2026-76689; classtype:attempted-admin; sid:7668901; rev:1;)

Elastic Detection

sequence by source.ip, destination.ip with maxspan=30s
  [network where http.request.method in ("POST","PUT") and
     http.request.body.bytes > 8000 and
     http.url : "*config*"]
  [process where event.action == "started" and
     process.parent.name : "*orchestrator*"]

Splunk SPL Query

index=proxy OR index=web sourcetype=access_combined
| search method IN ("POST","PUT") uri_path="*config*"
| eval request_len=len(request_body)
| where request_len > 8000
| stats count min(_time) as firstTime max(_time) as lastTime by src_ip uri_path method
| where count > 0
| convert ctime(firstTime) ctime(lastTime)

Wazuh OSSEC Rule

<group name="aruba,edgeconnect,cve-2026-76689,">
  <rule id="766890" level="10">
    <decoded_as>json</decoded_as>
    <field name="http.method">POST|PUT</field>
    <field name="url" type="pcre2">(?i)config|orchestrator</field>
    <description>CVE-2026-76689: Potential Aruba EdgeConnect Orchestrator configuration buffer overflow attempt</description>
    <mitre>
      <id>T1190</id>
    </mitre>
  </rule>
</group>

Mitigation & Patch Guidance

Patch confidence: 0/4 (UNPATCHED — no patch evidence from any tracked source). AFFECTED_VERSION and POC_STATUS: no public exploit or PoC available.

1. Immediate mitigations: Restrict network access to the orchestrator administrative interface to trusted management segments only; do not expose the admin UI to untrusted networks. Enforce strong authentication and least privilege, and rotate administrative credentials in case they are already compromised. Monitor for oversized or anomalous configuration uploads as described in the detection rules above. Segment the orchestrator so that a compromise cannot automatically pivot into the managed edge device fabric.

2. Patch/upgrade steps: No vendor patch has been identified from tracked sources at time of reporting. Monitor the Aruba Networks (HPE) security advisory portal for a patched firmware/build release, and apply it as soon as it becomes available. Verify the fixed version against the vendor advisory once published; no specific fix version is known.

3. Long-term hardening: Enable the vendor's built-in mitigations where available (e.g., stack canaries / ASLR at the platform level), consistently patch management-plane infrastructure, audit administrative actions and configuration changes, and reduce the orchestrator's attack surface by restricting out-of-band administrative access. Given the root-level RCE potential, treat the orchestrator as a tier-0 asset with strict change control and continuous monitoring.

References

• NVD — CVE-2026-76689: https://nvd.nist.gov/vuln/detail/CVE-2026-76689
• CWE-121 (Stack-based Buffer Overflow): https://cwe.mitre.org/data/definitions/121.html
• MITRE ATT&CK T1190 — Exploit Public-Facing Application: https://attack.mitre.org/techniques/T1190/
• Aruba Networks (HPE) Security Advisories — monitor for an advisory addressing CVE-2026-76689: https://www.arubanetworks.com/support-services/security-bulletins/
• CISA KEV Catalog (CVE listed as NO as of reporting): https://www.cisa.gov/known-exploited-vulnerabilities-catalog
• EPSS score data: https://api.first.org/data/v1/epss?cve=CVE-2026-76689
• No threat actor campaign or exploit-in-the-wild evidence was identified at time of reporting.