Host OS failure via unchecked network writes
Published Jan 28, 2026 · Updated Jan 28, 2026
Stack-based buffer overflow in Johnson Controls iSTAR Configuration Utility 6.9.7 and earlier allows remote attackers to cause host OS failure. NanSocket::Receive writes received data past a stack buffer; CICUApp and sprintf paths also write out of bounds or format absent string data. The attack requires no privileges but passive user interaction, and the published consequence is limited to operating-system failure.
Summary
What happened
Stack-based buffer overflow in Johnson Controls iSTAR Configuration Utility 6.9.7 and earlier allows remote attackers to cause host OS failure. NanSocket::Receive writes received data past a stack buffer; CICUApp and sprintf paths also write out of bounds or format absent string data. The attack requires no privileges but passive user interaction, and the published consequence is limited to operating-system failure.
The record
- CVE
- CVE-2025-26386
- Published
- Jan 28, 2026
- Updated
- Jan 28, 2026
- Vendor
- Johnson Controls
- Product
- iSTAR Configuration Utility
- Classifications
- CWE-121, T1499
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jan 28, 2026CVE publishedPublication date reported by the CVE source.
- Jan 28, 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.
- Affected versionversion=iSTAR Configuration Utility (ICU) tool version 6.9.7 and prior
What conditions does exploitation require?
What is affected?
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.
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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