Summary
CVE-2026-76726 is an authentication bypass vulnerability affecting the API endpoint of HPE Networking Instant ON access points. If certain preconditions outside the attacker’s control are met, an unauthenticated remote attacker can bypass network access controls and obtain unauthorized access to restricted networks. The flaw carries a CVSS v3.1 base score of 8.1 (High) and was disclosed by HPE on September 29, 2026 as part of a broader advisory covering 18 vulnerabilities in Instant ON.
Technical details
- Root cause: an authentication bypass condition in the API endpoint exposed by HPE Networking Instant ON devices, allowing access-control checks to be circumvented.
- Trigger conditions: exploitation depends on certain preconditions being satisfied that are outside the attacker’s control; no authentication or user interaction is required once those conditions are met.
- Attack vector: network-based (AV:N), with high attack complexity (AC:H) and no privileges required (PR:N).
- Impact: successful exploitation allows an unauthenticated remote attacker to bypass network access controls and gain unauthorized access to restricted networks, with high impact to confidentiality, integrity, and availability.
Affected software
- HPE Networking Instant ON, all versions from 0.0.0.0 through 3.4.1.0
Severity
- CVSS v3.1 Base Score: 8.1 (High)
- Vector:
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Mitigation and recommended actions
- Immediate: Upgrade affected HPE Networking Instant ON devices to firmware version 3.4.2.0 or later, which HPE has released to address this and related vulnerabilities disclosed in the same advisory.
- If immediate patching is not possible: restrict access to the device’s management and API interfaces to trusted, segmented networks (e.g., a dedicated management VLAN), disable unnecessary remote management access, and monitor device logs for anomalous API activity until the firmware update can be applied.