UC-1200A Series: Missing Cryptographic Step
CVE-2026-9266 is a high-severity missing cryptographic step vulnerability in UC-1200A Series from Moxa, with a CVSS 4.0 base score of 7.0 out of 10. It can be exploited with physical access to the device by an unauthenticated attacker, without any action from a user. Affected UC-1200A Series versions: 1.0 through 1.4. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.07% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of UC-1200A Series you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on moxa.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Moxa | UC-1200A Series | 1.0 through 1.4 | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- PhysicalThe attacker must physically touch the device.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Attack requirements
- NoneThe attack does not depend on a particular deployment or configuration.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Confidentiality (vulnerable system)
- HighSerious loss of confidentiality on the vulnerable system.
- Integrity (vulnerable system)
- HighSerious loss of integrity on the vulnerable system.
- Availability (vulnerable system)
- HighSerious loss of availability on the vulnerable system.
- Confidentiality (other systems)
- NoneNo loss of confidentiality on systems beyond the vulnerable one.
- Integrity (other systems)
- NoneNo loss of integrity on systems beyond the vulnerable one.
- Availability (other systems)
- NoneNo loss of availability on systems beyond the vulnerable one.
Vector: CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. Scored by CNA (moxa.com).
Official description
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.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Missing Cryptographic Step
The product does not implement a required step in a cryptographic algorithm, resulting in weaker encryption than advertised by the algorithm.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Recent Missing Cryptographic Step vulnerabilities
- 7.5 High severity
- 7.5 High severity
- 9.1 Critical severity
- 7.5 High severity
- 8.7 High severity
- 7.5 High severity
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