CVE-2026-9266: high-severity vulnerability in Moxa UC-1200A Series

A Missing Required Cryptographic Step vulnerability has been identified in Moxa's embedded Linux firmware for industrial computers and controllers. This vulnerability represents an incomplete remediation of CVE-2026-0714. The firmware introduced TPM2 parameter encryption as a countermeasure against CVE-2026-0714. However, an omission in the authorization session configuration causes the parameter encryption to provide no effective protection. An attacker with invasive physical access to the device can still capture TPM communications on the SPI bus and derive the LUKS disk encryption key in plaintext. While successful exploitation results in full compromise of the encrypted disk volume, the attack requires invasive physical access, including opening the device and attaching external equipment to the SPI bus. Remote exploitation is not possible, and the attack does not affect any downstream systems.