CVE-2026-73749 Overview
CVE-2026-73749 is a critical vulnerability affecting a daemon in HPE Aruba Networking AOS-CX. The flaw stems from improper processing of malformed input in a network-facing service. An unauthenticated remote attacker can exploit this weakness by sending specially crafted packets to the affected daemon. Successful exploitation results in remote code execution with elevated privileges on the switch operating system.
The vulnerability is classified under [CWE-284: Improper Access Control] and impacts the control plane of AOS-CX switches used in enterprise and data center networks. Compromise of these devices grants attackers control over routing, traffic inspection, and lateral movement paths.
Critical Impact
Unauthenticated remote code execution with elevated privileges on AOS-CX network infrastructure devices, enabling attackers to pivot across the network fabric.
Affected Products
- HPE Aruba Networking AOS-CX (see the HPE Security Bulletin for specific affected versions)
- AOS-CX switch platforms exposing the vulnerable daemon
- Network deployments where the management or control-plane service is reachable
Discovery Timeline
- 2026-09-01 - CVE-2026-73749 published to the National Vulnerability Database (NVD)
- 2026-09-03 - Last updated in NVD database
Technical Details for CVE-2026-73749
Vulnerability Analysis
The vulnerability resides in a daemon running on AOS-CX switches. The service accepts network input and fails to validate the structure of incoming packets. Malformed input triggers improper processing paths inside the daemon, allowing attacker-controlled data to influence execution flow.
Because the daemon runs with elevated privileges on the switch, exploitation grants attackers execution rights on the network device itself. This exposes routing tables, ACL configurations, credentials cached on the device, and traffic transiting the switch.
Root Cause
The issue is categorized under [CWE-284: Improper Access Control]. The affected daemon does not adequately enforce restrictions on the origin, format, or contents of packets it processes. Inputs that should be rejected instead reach parsing and handling routines that assume well-formed data, producing memory corruption or logic errors that lead to code execution.
Attack Vector
Exploitation requires network reachability to the vulnerable daemon. No authentication, user interaction, or prior foothold is required. An attacker sends specially crafted packets to the affected service, and the daemon processes them incorrectly. Switches that expose the vulnerable service to untrusted VLANs, management networks reachable from user segments, or the internet are the highest-risk targets. The vulnerability affects confidentiality, integrity, and availability of the switch and the traffic it carries.
No public proof-of-concept or exploit code is currently listed for CVE-2026-73749. Refer to the HPE Security Bulletin for vendor technical details.
Stop Remote Code Execution Before It Runs
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Stop Exploit AttemptsDetection Methods for CVE-2026-73749
Indicators of Compromise
- Unexpected process spawns, crashes, or restarts of AOS-CX daemons in switch logs
- Anomalous inbound traffic to switch management or control-plane services from user VLANs or untrusted networks
- Unauthorized configuration changes, new local accounts, or altered ACLs on AOS-CX devices
- Outbound connections from switch management interfaces to unknown external hosts
Detection Strategies
- Monitor AOS-CX syslog and event streams for repeated daemon faults, segmentation errors, or authentication anomalies
- Baseline normal management-plane traffic and alert on protocol deviations or malformed packets directed at switch services
- Correlate switch telemetry with NetFlow or sFlow to identify lateral movement originating from network devices
Monitoring Recommendations
- Forward AOS-CX logs to a centralized SIEM and apply detection rules for daemon crashes and configuration tampering
- Restrict and monitor access to switch management interfaces using out-of-band management networks
- Alert on any administrative session or CLI activity that does not originate from approved jump hosts
How to Mitigate CVE-2026-73749
Immediate Actions Required
- Apply the fixed AOS-CX firmware version listed in the HPE Security Bulletin as soon as possible
- Inventory all AOS-CX switches and identify devices running vulnerable software versions
- Restrict network reachability of the affected daemon to trusted management subnets only
- Audit switch configurations and account activity for signs of prior compromise
Patch Information
HPE has published guidance and fixed software versions in the HPE Security Bulletin (hpesbnw05134en_us). Administrators should upgrade AOS-CX to the versions identified as remediated by HPE. Confirm the fix version against your specific switch model and current firmware branch before deployment.
Workarounds
- Place switch management and control-plane services on isolated, out-of-band networks unreachable from user or internet segments
- Apply control-plane policing and ACLs to drop traffic to the vulnerable daemon from untrusted sources
- Disable the affected service on devices that do not require it, where supported by AOS-CX configuration
- Enforce strict network segmentation between administrative jump hosts and switch management interfaces
# Example: restrict management access to AOS-CX via ACL on the management VRF
# Consult HPE documentation for the exact syntax on your platform version
switch(config)# access-list ip MGMT-ACL
switch(config-acl-ip)# 10 permit tcp 10.10.0.0/24 any
switch(config-acl-ip)# 20 deny any any count
switch(config)# interface mgmt
switch(config-if-mgmt)# ip access-group MGMT-ACL in
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
