VulnerabilityPublished 21 May 2026Updated 30 Jul 2026

CVE-2026-5434: Honeywell International Control Network Module (CNM) · Insertion of Sensitive Information into Externally-Accessible File or Directory

Affects Honeywell International Control Network Module (CNM)Source CVE Database V5

Not known to be exploited · CVSS 5.9 Medium.

Data as of 27 Oct 2026, 05:11 UTC

CVSS 3.1 base score

5.9Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.2% chance of exploitation in 30 days – higher than 10% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

Attack Vector: Network
Attack Complexity: High
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: None
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: High: A successful attack depends on conditions beyond the attacker's control. That is, a successful attack cannot be accomplished at will, but requires the attacker to invest in some measurable amount of effort in preparation or execution against the vulnerable component before a successful attack can be expected. For example, a successful attack may require an attacker to: gather knowledge about the environment in which the vulnerable target/component exists; prepare the target environment to improve exploit reliability; or inject themselves into the logical network path between the target and the resource requested by the victim in order to read and/or modify network communications (e.g., a man in the middle attack).
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 21 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
Honeywell International Inc.Control Network Module (CNM)	Affected >=100.1 <=110.2	Fixed in–

AI-suggested

Honeywell recommends updating the Control Network Module (CNM) to the most recent version 200.1. This update is the primary remediation step to address the vulnerability. There are no indications that the vulnerability is already mitigated or that no action is required.

Description

CVE-2026-5434 is a vulnerability in Honeywell International Inc.'s Control Network Module (CNM) that involves the insertion of sensitive information into an unintended directory. This could allow an attacker to probe system files and potentially gain unintended access to protected data. The affected CNM versions include 100.1, 101.1, 110.1, and 110.2. Honeywell recommends updating to the most recent version 200.1 to address this issue. The vulnerability has a medium severity score of 5.9 and does not have any known exploits in the wild.

Impact

An attacker could potentially access sensitive information that was improperly stored in an externally accessible directory, leading to unauthorized disclosure of protected data. The vulnerability does not affect system integrity or availability. The medium CVSS score reflects the moderate risk due to the high attack complexity and lack of required privileges or user interaction.

Summary

The vulnerability identified as CVE-2026-5434 (CWE-538) affects Honeywell's Control Network Module (CNM) versions 100.1, 101.1, 110.1, and 110.2. It involves the insertion of sensitive information into directories that are externally accessible, which could be probed by an attacker to access protected data. The CVSS v3.1 score is 5.9, indicating medium severity, with network attack vector, high attack complexity, no privileges required, no user interaction, and high confidentiality impact but no integrity or availability impact. Honeywell advises updating to version 200.1 to mitigate this vulnerability.

CWE-538Insertion of Sensitive Information into Externally-Accessible File or Directory (opens in a new tab)
Base weaknessOWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The product places sensitive information into files or directories that are accessible to actors who are allowed to have access to the files, but not to the sensitive information.
Architecture and Design · Operation · System Configuration
Do not expose file and directory information to the user.
OWASP Cheat Sheets
Error Handling (opens in a new tab)
Logging (opens in a new tab)
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V8.3.4 (opens in a new tab)
V14.3.3 (opens in a new tab)
V7.3.3 (opens in a new tab)
Attack patterns
WSDL Scanning (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

honeywell.com/us/en/product-security (opens in a new tab)

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 6 Aug 2026, 17:32 UTC

WeaknessesCWE-538

Technical details

References

Community reviews

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