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CVE-2026-34494NVD status: Deferred

Neo Series MVP2: On-Chip Debug and Test Interface With Improper Access Control

CVE-2026-34494 is a high-severity on-chip debug and test interface with improper access control vulnerability in Neo Series MVP2 from Johnson Controls, with a CVSS 4.0 base score of 7.2 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, but only if a user takes part, for example by opening a link or file. The record lists version 3.3b63 as the first without the flaw, so updating Neo Series MVP2 to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.24% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Neo Series MVP2 to 3.3b63 or a later version.
  2. Read the advisory on johnsoncontrols.com for workarounds and exact fixed builds.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
  4. Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.

Affected products and versions

VendorProductAffected versionsFixed in
Johnson ControlsNeo Series MVP2before 3.3b633.3b63

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
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
HighSuccess depends on conditions outside the attacker's control.
Attack requirements
NoneThe attack does not depend on a particular deployment or configuration.
Privileges required
NoneNo account or login is needed.
User interaction
ActiveA user must deliberately do something unusual, such as dismissing a warning.
Confidentiality (vulnerable system)
NoneNo loss of confidentiality on the vulnerable system.
Integrity (vulnerable system)
NoneNo loss of integrity on the vulnerable system.
Availability (vulnerable system)
HighSerious loss of availability on the vulnerable system.
Confidentiality (other systems)
HighSerious loss of confidentiality on systems beyond the vulnerable one.
Integrity (other systems)
HighSerious loss of integrity on systems beyond the vulnerable one.
Availability (other systems)
HighSerious loss of availability on systems beyond the vulnerable one.

Vector: CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:H/SI:H/SA:H/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 (jci.com).

Official description

- On-Chip Debug Interface vulnerability in Johnson Controls Neo Series MVP2 allows Collect Data from Common Resource Locations. This issue affects Neo Series MVP2: before 3.3b63.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: On-Chip Debug and Test Interface With Improper Access Control

The chip does not implement or does not correctly perform access control to check whether users are authorized to access internal registers and test modes through the physical debug/test interface.

How developers prevent this class of flaw

  • If feasible, the manufacturer should disable the JTAG interface or implement authentication and authorization for the JTAG interface. If authentication logic is added, it should be resistant to timing attacks. Security-sensitive data stored in registers, such as keys, etc. should be cleared when entering debug mode.

More On-Chip Debug and Test Interface With Improper Access Control vulnerabilities (CWE-1191)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Recent On-Chip Debug and Test Interface With Improper Access Control vulnerabilities

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