CVE-2026-65198: CWE-321 Use of hard-coded cryptographic key in Huawei openUBMC

Huawei's openUBMC firmware includes a default SNMPv3 User-based Security Model (USM) key hard-coded in the build customization files. The same cryptographic key is used for both authentication and privacy, and it is identical across all devices shipped with affected versions. This key is recoverable from the open-source build and is not rotated or changed by administrator password resets. Because SNMP access grants full device administration privileges, an attacker who obtains this key can authenticate to SNMPv3 on any affected device and decrypt SNMPv3 traffic, potentially allowing unauthorized system resets and firmware upgrades.

The vulnerability allows an attacker who obtains the hard-coded SNMPv3 key to fully authenticate to the SNMP service on any affected device, bypassing normal authentication controls. This grants the attacker full administrative privileges, including the ability to reset the system and perform firmware upgrades. Confidentiality is also compromised as SNMPv3 traffic can be decrypted. This poses a significant risk to device integrity and availability.

No patch links or vendor advisories indicating a fix are provided. Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, administrators should consider disabling SNMPv3 access or restricting it to trusted networks to mitigate risk. Changing the administrator password does not mitigate this vulnerability as the hard-coded key remains unchanged.