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Fencer Vulns
critical 9.3

CVE-2025-53696 json

iSTAR Ultra performs a firmware verification on boot, however the verification does not inspect certain portions of the firmware.

published 2025-07-28 15 mo ago modified 2026-06-17 4 mo ago also EUVD-2025-22915

cvss
9.3
version 4.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.1%
EPSS 0.1% chance of exploitation in 30 days, percentile 1%
public exploits
0
none known

Summary

iSTAR Ultra performs a firmware verification on boot, however the verification does not inspect certain portions of the firmware. These firmware parts may contain malicious code. Tested up to firmware 6.9.2, later firmwares are also possibly affected.

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

cisa ICSA-25-224-02 updated cvss 8.8

Johnson Controls iSTAR Ultra, iSTAR Ultra SE, iSTAR Ultra G2, iSTAR Ultra G2 SE, iSTAR Edge G2 (Update A)

  • Johnson Controls iSTAR Ultra <=6.9.2.CU02
    affected: vendor fix, mitigation “Johnson Controls made firmware version 6.9.3 available in 2024 to fix CVE-2025-53695 and lower the risk of exploitation for CVE-2025-53696, CVE-2025-53697, and CVE-2025-53700.” johnsoncontrols.com
  • Johnson Controls iSTAR Ultra SE <=6.9.2.CU02
    affected: mitigation “Johnson Controls made firmware version 6.9.3 available in 2024 to fix CVE-2025-53695 and lower the risk of exploitation for CVE-2025-53696, CVE-2025-53697, and CVE-2025-53700.” johnsoncontrols.com

From CISA ICS and IT advisories (CSAF, https://github.com/cisagov/CSAF), a U.S. Government work; changed: reduced to products, statuses and remediations. CISA notification · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
15 mo ago

Exploit prediction

0.10% chance of exploitation in the next 30 days, higher than 1% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 4.0 9.3 CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
CNA 4.0 9.3 CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/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

Affected products

  • Johnson Controls, Inc iSTAR Ultra

Classification

Weakness
  • CWE-494 Download of Code Without Integrity Check

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.