CVE-2026-33389: Nozomi Networks Guardian/CMC and Arc improper certificate validation in Smart Polling

CVE-2026-33389 · Severity: high · CVSS 7.5 · Published 2026-09-08

Nozomi Networks Guardian, CMC, and Arc are industrial monitoring and management platforms used to supervise and control critical infrastructure devices. The Smart Polling feature establishes encrypted connections to monitored devices but fails to validate the remote device's identity, allowing an attacker positioned on the network between the sensor and a polled device to intercept credentials and access or disrupt the monitored systems.

Technologies: Nozomi Networks Guardian. Vendors: Nozomi Networks.

Quick answers

Is CVE-2026-33389 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-33389 being exploited in the wild.
How severe is CVE-2026-33389?
High severity, with a CVSS score of 7.5, published 8 September 2026.
Which products and versions are affected?
Nozomi Networks Guardian before 26.3.0.
Is there a fix for CVE-2026-33389?
A patch was published on 2026-09-08: Patches released: Guardian/CMC v26.3.0 and Arc v2.7.0 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-33389 attacked?
It is attacked over the network or from the adjacent network, in a network appliance.
Am I affected by CVE-2026-33389?
Check whether you run Nozomi Networks Guardian at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

The vulnerability is an improper certificate/host key validation issue (CWE-671: Lack of Administrator Control over Security) in the Smart Polling functionality. During encrypted polling sessions, the affected products do not validate the remote host's certificate or identity, and no configuration option exists to enable validation. A man-in-the-middle attacker on the network path between a sensor and a polled device can impersonate the target device, intercept encrypted traffic, and capture authentication credentials transmitted during polling. The captured credentials can be replayed to gain unauthorized access to the polled device or other systems sharing the same credentials. The vulnerability requires network proximity and active attack during a polling session; patches are available in Guardian/CMC v26.3.0 and Arc v2.7.0 and later.

Affected products

  • Nozomi Networks Guardian before 26.3.0
  • Nozomi Networks CMC before 26.3.0
  • Nozomi Networks Arc before 2.7.0

Timeline

  • 2026-09-08: disclosed
  • 2026-09-08: patched: Patches released: Guardian/CMC v26.3.0 and Arc v2.7.0

References

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