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Johnson Controls T2000 EUVDEUVD-2026-67140

| CVE-2026-64896 MEDIUM
Improper Access Control (CWE-284)
2026-08-27 jci GHSA-h5wr-2px2-58v4
5.2
CVSS 4.0 · Vendor: jci
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Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain

  1. Access
    Gain physical access to T2000 unit
  2. Delivery
    Connect to exposed hardware debug/test interface
  3. Exploit
    Bypass ACL enforcement on interface
  4. Execution
    Issue unauthorized commands
  5. Impact
    Disrupt device availability or modify device state

Vulnerability Assessment

Weakness
CWE
OWASP Top 10:2025
A01:2025 - Broken Access Control
ASVS 5.0
V8 - Authorization Access control enforcement
MITRE ATT&CK

1 technique across 1 tactic: Defense Evasion

The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up.

Exploitation Conditions

Physical access to the T2000 hardware is the primary and mandatory prerequisite, confirmed by the CVSS 4.0 AV:P (Physical) attack vector. The debug or test interface must be physically accessible on the device - standard production units appear to leave this interface exposed. No authentication credentials are required to interact with the interface (PR:N), and no user interaction or network connectivity is needed. Exploitation is inherently limited to individuals who can physically reach the device. Devices installed in locked, access-controlled enclosures or server rooms with enforced visitor logging represent a significantly reduced exposure surface. There is no indication that this vulnerability is exploitable remotely or over any network interface.

Impact

The CVSS 4.0 score of 5.2 (Medium) accurately reflects the physical access constraint (AV:P), which substantially limits opportunistic or remote exploitation and rules out network-based mass attack campaigns. The high availability impact (VA:H) is the most operationally significant signal - in OT environments where T2000 units control HVAC, access, or facility systems, device disruption can cascade into safety or business continuity incidents. Low integrity impact (VI:L) indicates limited configuration modification is also possible. No EPSS data was provided, and the absence of a CISA KEV listing and any known public POC indicates this has not been observed in active exploitation at time of analysis. A notable discrepancy exists: the 'Information Disclosure' tag in the input conflicts with the CVSS 4.0 VC:N (no confidentiality impact to the vulnerable system) - whether data exposure is a realistic secondary outcome should be confirmed against the Johnson Controls vendor advisory. Overall, real-world risk is moderate, primarily relevant to facilities with weak physical security controls around deployed T2000 hardware rather than internet-exposed environments.

Exploit ScenarioDerived

An attacker with physical access - such as an authorized contractor, a social-engineered insider, or a physical intruder who bypasses building security - connects directly to the T2000's exposed debug or test interface port and issues commands that are not subject to normal ACL enforcement. This could disable the controller, disrupting HVAC or facility management functions, or allow limited modification of device state. No public exploit code is known, so exploitation currently requires knowledge of the debug interface protocol and physical hardware access.

This Month Plan within 30 days. Why: MEDIUM severity (CVSS 4.0-6.9).
Patch available 0.1% exploitation probability (EPSS)

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AnalysisAIv1 – Aug 27, 2026

Improper access control on the debug and test interface of the Johnson Controls T2000 building automation controller exposes restricted device functionality to anyone with physical access, requiring no authentication. Versions prior to 31.6 are affected, with the primary risk being high availability disruption of the device alongside limited integrity modification capability. No public exploit code or active exploitation has been identified at time of analysis, and a vendor-released patch is available.

RemediationAI

Upgrade T2000 firmware to version 31.6 or later, per the vendor patch availability confirmed by Johnson Controls and the EUVD-2026-67140 entry. Consult the Johnson Controls Trust Center advisory at https://www.johnsoncontrols.com/trust-center/cybersecurity/security-advisories for official upgrade procedures and release notes. As a compensating control prior to patching, implement physical access restrictions for all T2000 units: install locked enclosures, enforce visitor and contractor access logging, and restrict keycard or physical access to equipment rooms. If the device design permits disabling the debug interface port physically (e.g., via a jumper or enclosure modification), evaluate this option against ongoing maintenance requirements, as disabling it may impede legitimate diagnostic work. Conduct a physical security audit of all T2000 installations in sensitive facilities as an immediate interim step.

Affected VersionsENISA

T2000 0 <31.6

Affected Packages

euvd t2000 fix: 31.6

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 1 package in euvd

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

The T2000 is a Johnson Controls building automation controller deployed in HVAC and facility management environments, identified by CPE cpe:2.3:a:johnson_controls:t2000:*:*:*:*:*:*:*:*. The vulnerability involves a debug or test interface - likely a physical hardware port such as UART, serial, or a diagnostic connector - that lacks proper access control enforcement, allowing access to functionality not constrained by ACLs. No CWE is formally assigned, but the vulnerability class aligns with CWE-284 (Improper Access Control) and CWE-912 (Hidden Functionality), both common in embedded OT/IoT devices where diagnostic interfaces are designed for manufacturing or maintenance use but not adequately secured in production deployments. The CVSS 4.0 vector confirms physical proximity is required (AV:P) with no attack requirements beyond device access.

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Severity by source

Vendor (jci) PRIMARY 5.2 MEDIUM
CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N
vuln.today AI 5.2 MEDIUM

Physical access required per description and AV:P; debug interface requires no privileges; high availability impact but no confidentiality impact and unchanged scope.

3.1 AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H
4.0 AV:P/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N

Primary rating from Vendor (jci).

CVSS VectorVendor: jci

Attack Vector
Physical
Attack Complexity
Low
Attack Requirements
None
Privileges Required
None
User Interaction
None
Vulnerable system: Confidentiality
None
Vulnerable system: Integrity
Low
Vulnerable system: Availability
High
Subsequent system: Confidentiality
None
Subsequent system: Integrity
None
Subsequent system: Availability
None

Lifecycle Timeline

1
Patch available
Aug 27, 2026 - 18:02 EUVD

DescriptionCVE.org

Debug and Test Interface With Improper Access Control vulnerability in Johnson Controls T2000 allows Accessing Functionality Not Properly Constrained by ACLs.

This issue affects T2000: before 31.6.

Threat Intelligence Overview

EPSS Score
0.1%
Top 96% exploitable
Prevalence
Low
niche industrial building automation controller, limited enterprise footprint
Data Quality
5 sources
Confidence: Medium

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue
Severity MEDIUM
CISA KEV No
Public POC No
EPSS 0.1%
Patch available Yes
Active threat No
Deciding rule
MEDIUM severity (CVSS 4.0-6.9)
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived
Defer
Exploitation
None
System Exposure· derived
Small
Automatable
No
Human Impact· derived
Medium
Technical Impact
Partial

Priority Score

26
Low Medium High Critical
KEV: 0
EPSS: 0
CVSS: +26
PoC: 0
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

Authentication bypass attacks exploit flaws in the verification mechanisms that control access to systems and applications.

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