CVE-2026-21655

Adjacent-network code execution via unsafe deserialization

Published Jul 23, 2026 · Updated Jul 23, 2026

Deserialization of untrusted data in Johnson Controls victor 2.9 allows remote attackers on an adjacent network to execute arbitrary code. Johnson Controls has not identified the receiving component, serialized format, or specific unsafe deserialization operation. No authentication or user interaction is required; successful exploitation runs attacker-controlled code on the Windows application server and connected clients.

CVSS severity8.7
High
EPSS probability0.49%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Deserialization of untrusted data in Johnson Controls victor 2.9 allows remote attackers on an adjacent network to execute arbitrary code. Johnson Controls has not identified the receiving component, serialized format, or specific unsafe deserialization operation. No authentication or user interaction is required; successful exploitation runs attacker-controlled code on the Windows application server and connected clients.

The record

CVE
CVE-2026-21655
Published
Jul 23, 2026
Updated
Jul 23, 2026
Vendor
Johnson Controls
Product
victor
Classifications
CWE-502, CAPEC-586, T1203
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 23, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 23, 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=2.9 <3.0

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

Johnson Controls · victorversion=2.9 <3.0

Published CVSS scores

8.7Johnson ControlsCVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-502Deserialization of Untrusted Data
CAPEC-586Object Injection
T1203Exploitation for Client Execution

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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