CVE-2026-21662Network attack vector

Malicious file storage via unrestricted upload

Published Jul 31, 2026 · Updated Jul 31, 2026

Unrestricted file upload in Johnson Controls OpenBlue Employee before 2025.3.1 allows remote authenticated users to store malicious files. Johnson Controls has not disclosed the affected upload endpoint or the validation failure that permits dangerous file types. High application privileges and passive interaction by another user are required; malicious uploaded content can expose or alter application data.

CVSS severity4.8
Medium
EPSS probability0.28%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Unrestricted file upload in Johnson Controls OpenBlue Employee before 2025.3.1 allows remote authenticated users to store malicious files. Johnson Controls has not disclosed the affected upload endpoint or the validation failure that permits dangerous file types. High application privileges and passive interaction by another user are required; malicious uploaded content can expose or alter application data.

The record

CVE
CVE-2026-21662
Published
Jul 31, 2026
Updated
Jul 31, 2026
Vendor
Johnson Controls
Product
OpenBlue Employee
Classifications
CWE-434, CAPEC-17, T1105
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Jul 31, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 31, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <2025.3.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

Johnson Controls · OpenBlue Employeeversion=0 <2025.3.1

Published CVSS scores

4.8Johnson ControlsCVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-434Unrestricted Upload of File with Dangerous Type
CAPEC-17Using Malicious Files
T1105Ingress Tool Transfer

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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