CVE-2026-3356 Anritsu CVE debrief

Who should care

Operators and defenders responsible for Anritsu Remote Spectrum Monitor deployments, especially industrial control system and OT environments where the management interface may be reachable from shared or untrusted networks.

Technical summary

According to the CISA advisory, unauthorized users can access and manipulate the MS27102A management interface because authentication can be bypassed and cannot be enabled or configured on the device. The source rates the issue with CVSS 3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H, indicating remote, unauthenticated impact across confidentiality, integrity, and availability. CISA also notes that Anritsu has no plans to fix the issue and recommends deploying the product only within secure network environments.

Defensive priority

Immediate

Recommended defensive actions

• Restrict management interface exposure to trusted, segmented networks only.
• Do not place affected devices on directly reachable or internet-accessible networks.
• Review firewall, ACL, and routing controls to limit who can reach the management interface.
• Treat the device as lacking built-in authentication and compensate with external network controls.
• Follow CISA ICS recommended practices and defense-in-depth guidance for OT environments.
• Contact Anritsu Technical Support at 1-800-267-4878 for vendor guidance.

Evidence notes

The source advisory explicitly says the MS27102A has an authentication bypass, that unauthorized users can access and manipulate the management interface, and that there is no mechanism to enable or configure authentication. It also states Anritsu has no plans to fix the issue and recommends deployment only within secure network environments. The advisory’s SSVC note is included as provided: SSVCv2/E:N/A:Y/2026-03-30T06:00:00.000000Z.

Official resources