CyberSecBulletin
CVE-2026-33389NVD status: Awaiting Analysis

Guardian: Lack of Administrator Control over Security

Published Updated By the CyberSecBulletin desk

CVE-2026-33389 is a high-severity lack of administrator control over security vulnerability in Guardian from Nozomi Networks, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, but only if a user takes part, for example by opening a link or file. The record lists version 26.3.0 as the first without the flaw, so updating Guardian to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.17% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Guardian to 26.3.0 or a later version.
  2. Update CMC to 26.3.0 or a later version.
  3. Update Arc to 2.7.0 or a later version.
  4. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
  5. Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.

Affected products and versions

VendorProductAffected versionsFixed in
Nozomi NetworksGuardianbefore 26.3.026.3.0
Nozomi NetworksCMCbefore 26.3.026.3.0
Nozomi NetworksArcbefore 2.7.02.7.0
SiemensRUGGEDCOM APE1808all versionsNot stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
HighSuccess depends on conditions outside the attacker's control.
Privileges required
NoneNo account or login is needed.
User interaction
RequiredA user must take an action such as opening a file or link.
Scope
ChangedThe attack can reach beyond the vulnerable component into other systems.
Confidentiality
HighAll data handled by the component can be read.
Integrity
LowLimited modification of data is possible.
Availability
LowPerformance or availability is reduced.

Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:L/A:L. Scored by CNA (nozominetworks.com).

Scoring systemScoreSeverityScored by
CVSS 4.05.3MediumCNA (nozominetworks.com)
CVSS 3.17.5HighCNA (nozominetworks.com)

Official description

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.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Lack of Administrator Control over Security

The product uses security features in a way that prevents the product's administrator from tailoring security settings to reflect the environment in which the product is being used.

More Lack of Administrator Control over Security vulnerabilities (CWE-671)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in Guardian

All Guardian vulnerabilities

Recent Lack of Administrator Control over Security vulnerabilities

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