Which versions are affected?

Affected product and version evidence is listed in the product table above. Current public advisories should be checked for exact version scope before patch targeting is finalized.

Is there active exploitation?

Active exploitation is not confirmed from current sources for CVE-2026-33389. If exploitation is not confirmed from current sources, teams should document that status and continue monitoring KEV, vendor, and telemetry updates.

No. CVE-2026-33389 is not listed in CISA KEV in the supplied enrichment data. KEV status should be monitored because it can change after initial disclosure or after exploitation becomes publicly confirmed.

Is there a public exploit?

1 public PoC repositories reported; 0 marked weaponized in current dataset. Public exploit or PoC availability should raise triage priority, especially for exposed or business-critical systems.

How can defenders detect it?

Start with web/proxy/WAF logs, application logs, network IDS/IPS where available. Look for vulnerability-class behavior, product errors, suspicious authentication events, exploit probes, and abnormal process activity based only on evidence that applies to the affected product.

How should teams prioritize it?

Prioritize CVE-2026-33389 using CVSS 7.5, EPSS 0%, KEV status, public PoC status, and asset exposure. Internet-facing, privileged, or business-critical deployments should be handled first.

Are workarounds available?

Workarounds are not confirmed from current sources. Fixed-version evidence is listed in the mitigation section above.

Which threat actors are linked publicly?

No public threat actor linkage is confirmed from current sources. Do not attribute exploitation to a threat actor unless the source evidence explicitly supports that linkage.

What should be done in the next 24 hours?

Identify exposed assets running affected vendor/product/version combinations. Prioritize based on EPSS, PoC availability, and external exposure. Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class. Open remediation tickets with affected assets, owners, evidence status, and detection coverage so decisions are traceable.

highpublic exploit

CVE-2026-33389

CVE-2026-33389 — Disabled and non-configurable certificate/host key validation in Smart Polling in Guardian/CMC before 26.3.0 and Arc before v2.7.0

Q: What is CVE-2026-33389?

CVE-2026-33389 is Disabled and non-configurable certificate/host key validation in Smart Polling in Guardian/CMC before 26.3.0 and Arc before v2.7.0. The supplied enrichment data classifies it as Unclassified mapped to CWE-671 CWE-671.

An improper certificate/host key validation vulnerability was discovered in the Smart Polling functionality, which established encrypted connections to target devices without validating the remote host's identity, and no option was provided to enable it. A man-in-the-middle attacker positioned between a sensor and a polled device can, during a polling session, impersonate the device and intercept the communication, including the credentials used to access it. The captured credentials can then be replayed to authenticate against the device itself or against other devices sharing the same credentials, allowing the attacker to access and tamper with the device's data and to disrupt its operations.

Published Sep 8, 2026Updated Sep 8, 2026Sources: NVD, Nozomi Networks (CNA), GitHub, GitHub Security Advisory, SOCRadar CTI

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the scoring sources call it.

Exploitation

Exploit code

public exploit, none observed

EPSS

ahead of 0% of scored CVEs

Affects

Nozomi Networks

3 products listed

CVSS base

7.5

high · 2 sources

CISA SSVC assessment

Three decision points CISA publishes for the CVEs it assesses · SSVC 2.0.3. A stakeholder decision, not a severity score.

CISA

Exploitation

None

none · proof-of-concept · active

Automatable

can an attacker script all four kill-chain steps

Technical impact

Partial

partial · total control of the vulnerable component

Remediation

The vendor's own words where we have them.

Upgrade Guardian/CMC to v26.3.0 or later. Upgrade Arc to v2.7.0 or later.

First 24 hours

Ordered from the record's own fields — exposure first, because you cannot patch what you have not found.

Identify exposed assets running affected vendor/product/version combinations.
Prioritize based on EPSS, PoC availability, and external exposure.
Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class.

Affected scope

Vendor, product and version as the advisories word them.

Vendor	Product	Versions	Status
Nozomi Networks	Guardian	0 to < 26.3.0	Vulnerable
Nozomi Networks	CMC	0 to < 26.3.0	Vulnerable
Nozomi Networks	Arc	0 to < 2.7.0	Vulnerable

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Availability

Low

Confidentiality

High

Integrity

Low

Scope

Changed

Attack Complexity

High

Attack Vector

Network

Privileges Req

None

User Interaction

Required

Every base score collected

Sources score independently and disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Source
7.5	CVSS 3.1	high	1.6	5.3	nozominetworks.com (CNA), Nozomi Networks (CNA), GHSA
5.3	CVSS 4.0	medium	—	—	Nozomi Networks (CNA)

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

What this weakness leads to

MITRE's own consequences and mitigations for the weakness class — the authority's wording, not guidance derived from the CVSS vector.

MITRE

CWE-671 · Lack of Administrator Control over Security

Varies by Context::

Weakness & attack patterns

CWE-671

Public exploit

Capability, not use: code existing is a different claim from anyone running it.

Repositories

Detection

Read off the CVSS vector and the weakness class. Starting points, not rules we have tested.

Search application, proxy, and WAF logs for requests touching /host.
Prioritize edge telemetry for network-reachable Guardian, CMC, Arc.
Monitor for scanner or exploit-pattern traffic after 1 public PoC repositories were reported.

web/proxy/WAF logsapplication logsnetwork IDS/IPS

Timeline

What happened to this CVE, newest first — with the readings a source repeats on a schedule counted underneath rather than listed.

2026
Added · CVSS 3.1 7.5 (AV:N)
Sep 8, 2026 · NVD
Initial · CVE published
Sep 8, 2026 · NVD
Added · GHSA-8g88-35qx-36v7 published (medium)
Sep 8, 2026 · GitHub Security Advisory
CVE published by MITRE.
Sep 8, 2026 · SOCRadar CTI

References

3 on the record

security.nozominetworks.com/NN-2026:20-01
Vendor Advisory
nvd.nist.gov/vuln/detail/CVE-2026-33389
NVD
github.com/advisories/GHSA-8g88-35qx-36v7
Exploit, Third Party Advisory

Elsewhere on this site

Nozomi Networksevery CVE for this vendor
Unclassifiedsame class
CWE-671other pages naming this weakness

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record1

What should defenders know first?

CVE-2026-33389 is Disabled and non-configurable certificate/host key validation in Smart Polling in Guardian/CMC before 26.3.0 and Arc before v2.7.0, a high vulnerability affecting Guardian, CMC, Arc from Nozomi Networks. The current evidence does not list it in CISA KEV, and the exploit status is: Active exploitation is not confirmed from current sources for CVE-2026-33389. Public exploit evidence is: 1 public PoC repositories reported; 0 marked weaponized in current dataset. The affected-version evidence is listed in the key facts and affected products tables. Defenders should first verify whether exposed or business-critical assets run those versions, then apply vendor patches or mitigations, restrict reachable attack surface, and preserve logs for detection review. CVSS 7.5 describes technical severity, while EPSS 0% helps estimate near-term exploit likelihood; neither replaces asset context. Unknown fields should remain explicit in tickets, and threat actor, IOC, victimology, or payload claims should not be added unless a cited source supports them. Monitor CISA KEV, vendor advisories, NVD changes, public PoC repositories, and internal telemetry for update triggers.