CVE-2026-73774: AOS-CX Buffer Overflow Vulnerability

CVE-2026-73774 Overview

CVE-2026-73774 is a buffer overflow vulnerability [CWE-120] in the underlying operating system of HPE Aruba Networking AOS-CX. An unauthenticated attacker on an adjacent network can send specially crafted packets to trigger the flaw. Successful exploitation results in limited disclosure or modification of information and disruption of the affected system. The vulnerability requires no authentication and no user interaction, but the attacker must reside on a logically adjacent network segment.

Critical Impact
Adjacent-network attackers can trigger memory corruption in AOS-CX switches to leak sensitive information and disrupt device availability without authentication.

Affected Products

HPE Aruba Networking AOS-CX (underlying operating system)
Switches running vulnerable AOS-CX firmware versions
Refer to the HPE Security Bulletin for the complete list of affected builds

Discovery Timeline

2026-09-01 - CVE-2026-73774 published to NVD
2026-09-02 - Last updated in NVD database

Technical Details for CVE-2026-73774

Vulnerability Analysis

The flaw is a classic buffer overflow condition [CWE-120] that occurs during packet processing in the AOS-CX operating system. The vulnerable code path parses incoming network packets without properly enforcing destination buffer bounds. When an attacker sends a specially crafted packet, adjacent memory regions can be read or overwritten. Because the impacted process operates on network data before authentication, exploitation requires no credentials.

The attack surface is limited to the adjacent network, meaning the attacker must reach the switch via a directly connected Layer 2 broadcast domain or an equivalent logically adjacent segment. This constraint reduces the exposure profile compared with fully remote flaws but remains meaningful for switches deployed in shared broadcast domains or misconfigured trunk links.

Root Cause

The root cause is a missing or insufficient length check during the copy of untrusted packet data into a fixed-size buffer within an AOS-CX system component. When the packet's declared or actual length exceeds the destination buffer, the copy operation writes beyond the intended boundary. This corrupts adjacent memory structures and, depending on layout, discloses residual memory contents back to the attacker or destabilizes the process.

Attack Vector

Exploitation requires network adjacency to the target switch. An attacker crafts malformed packets targeting the vulnerable protocol handler and transmits them to the affected AOS-CX device. No prior authentication, credentials, or user interaction is required. HPE has not indicated public exploitation, and no proof-of-concept code is currently listed in public databases. Technical details for CVE-2026-73774 are described in prose only because no verified exploit code is available. Consult the HPE Security Bulletin for vendor-provided technical specifics.

Detection Methods for CVE-2026-73774

Indicators of Compromise

Unexpected process restarts, crash logs, or coredumps generated by AOS-CX system daemons
Anomalous malformed packets on management VLANs or adjacent segments preceding switch instability
Unexplained management-plane reboots or transient loss of control-plane connectivity

Detection Strategies

Enable and centralize AOS-CX system and crash logs to identify signatures of memory corruption in packet-handling processes
Deploy network intrusion detection sensors on segments adjacent to critical switches to flag oversized or malformed protocol packets
Correlate switch stability events with packet capture data at ingress ports to identify the source of anomalous traffic

Monitoring Recommendations

Forward syslog and SNMP trap data from AOS-CX devices into a centralized SIEM for continuous review
Alert on repeated daemon restarts, kernel panics, or coredump generation on network infrastructure
Baseline expected control-plane and management-plane traffic to accelerate identification of anomalous adjacent-network packets

How to Mitigate CVE-2026-73774

Immediate Actions Required

Review the HPE Security Bulletin and identify AOS-CX versions running in the environment
Apply the vendor-supplied AOS-CX firmware update to all impacted switches during the next available maintenance window
Restrict Layer 2 adjacency to trusted devices by hardening port security, disabling unused ports, and enforcing VLAN segmentation

Patch Information

HPE Aruba Networking has published fixed firmware versions for AOS-CX. Consult the HPE Security Bulletin for the exact remediated build numbers that correspond to each affected switch platform. Apply updates through standard change control procedures.

Workarounds

Isolate management interfaces on dedicated VLANs that are unreachable from user or untrusted segments
Apply access control lists on adjacent interfaces to restrict which hosts may transmit control-plane protocol traffic to switches
Disable unused protocol handlers on AOS-CX where operationally feasible to reduce exposed parsing surface

bash

# Example: restrict management VLAN access on AOS-CX
configure terminal
vlan 4094
    name MGMT_ISOLATED
interface mgmt
    ip access-group MGMT_ACL in
ip access-list MGMT_ACL
    10 permit ip 10.10.0.0/24 any
    20 deny ip any any log