CVE-2026-34494
Raw 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:XCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2026-34494 is a high-severity On-Chip Debug and Test Interface With Improper Access Control (CWE-1191) vulnerability in Johnsoncontrols (inferred from references). Its CVSS base score is 7.2 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique OS Credential Dumping (T1003); ranked at the 14th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to AC-3 (Access Enforcement) and AC-6 (Least Privilege) — see the control section below for these in your framework.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-91071
Vulnerability Data
- 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.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
AC-3 directly requires enforcement of authorization checks on all logical access paths, which would block unauthorized use of the debug/test interface registers.
AC-6 requires restricting access rights to the minimum needed, limiting what an attacker reaching the debug interface can actually read or modify.
IA-3 requires device identification and authentication before any connection is established, which would apply to external debug or test equipment.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Authentication of hardware can help restrict debug interface use but is narrower than full access control.
Defining and enforcing access permissions directly addresses improper authorization to debug interfaces.
Managing physical access to assets covers control of on-chip debug/test ports and pins.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
A.8.25 mandates a secure-SDLC process (requirements, checkpoints, secure coding, testing, training) but does not itself perform or enforce access control on the chip's physical debug/test interface; the weakness can still be present and exploitable after the process completes.
Secure architecture principles include hardware access-control mechanisms for debug and test interfaces.
Security testing can discover improper debug access but does not itself implement the control.