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Nessus AgentApplication · Tenable

CVE-2026-2026

MEDIUM · 6.1 CVSS v3.1 Published 2026-02-13
Fix available
A fix is available. Upgrade to 11.0.4 / 11.1.2 or later.
See remediation →
63/100
Remediation priority · Elevated
Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
A vulnerability has been identified where weak file permissions in the Nessus Agent directory on Windows hosts could allow unauthorized access, potentially permitting Denial of Service (DoS) attacks.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

Weak file permissions on the Nessus Agent installation directory in Windows allows unauthorized local users to access or modify critical files, potentially enabling them to disrupt agent functionality through Denial of Service attacks.

MitigationRestrict file permissions on the Nessus Agent directory to enforce least-privilege access, ensuring only authorized administrators and the service account have write/modify access.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Nessus AgentApplication
Affected:< 11.0.4>= 11.1.0, < 11.1.2

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
High

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check installed Nessus Agent version
    Open Programs and Features (appwiz.cpl) or use PowerShell: Get-ItemProperty 'HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\*' | Where-Object {$_.DisplayName -like '*Nessus*'} | Select-Object DisplayName, DisplayVersion
    Affected if Version is less than 11.0.4 OR version is 11.1.0 or 11.1.1 (versions 11.1.0 through 11.1.1 are affected)
  2. Locate Nessus Agent installation directory
    Check the default installation path, typically C:\Program Files\Tenable\Nessus Agent or C:\Program Files (x86)\Tenable\Nessus Agent. Verify using: Get-ItemProperty 'HKLM:\SYSTEM\CurrentControlSet\Services\Tenable Nessus Agent' | Select-Object ImagePath
    Affected if Nessus Agent is installed on the system
  3. Review permissions on the Nessus Agent installation directory
    Right-click the installation folder, go to Properties > Security tab. Click Advanced to view detailed permissions. Check which users and groups have access and what level of permissions they possess.
    Affected if Users other than Administrators, SYSTEM, and the Nessus Agent service account have Modify, Write, or Full Control permissions
  4. Test write access for standard users
    Using a non-privileged user account or icacls from an elevated command prompt, run: icacls 'C:\Program Files\Tenable\Nessus Agent\*' to list permissions, or attempt to create/modify a test file in the directory using a standard user account.
    Affected if Standard (non-admin) users can successfully write or modify files in the installation directory
  5. Inspect permissions on critical Nessus agent files
    Run icacls on key files such as nessuscli.exe, nessus-service.exe, or conf files in the installation directory to verify which accounts have write access.
    Affected if Non-privileged users have Write or Modify permissions on executable or configuration files in the Nessus Agent directory

The environment is affected if Nessus Agent version is below 11.0.4 or between 11.1.0 and 11.1.1 inclusive, AND standard users have write or modify permissions on the installation directory or its critical files.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 11.0.4 / 11.1.2 or later
Fixed in 11.0.411.1.2
Interim mitigation

Restrict file permissions on the Nessus Agent directory to enforce least-privilege access, ensuring only authorized administrators and the service account have write/modify access.

Recommended fix High confidence

Nessus Agent 11.0.4 or later (for versions < 11.0.4); Nessus Agent 11.1.2 or later (for versions 11.1.0-11.1.1)

  1. 1. Verify the current Nessus Agent version by checking the installation or using 'nessuscli --version' or 'sc query tenableagent'
  2. 2. If running a version < 11.0.4, plan upgrade to version 11.0.4 or later
  3. 3. If running version 11.1.0 or 11.1.1, plan upgrade to version 11.1.2 or later
  4. 4. Download the appropriate Nessus Agent installer from the official Tenable downloads page
  5. 5. Create a backup of the current Nessus Agent configuration if needed
  6. 6. Run the installer to upgrade the Nessus Agent to the fixed version
  7. 7. Verify the upgrade was successful by checking the new version
  8. 8. Confirm file permissions on the Nessus Agent directory are properly restricted after upgrade

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Nessus Agent Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing1.0 h
  • Review / QA1.0 h
6.0 hours of engineering $1,090
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,744.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-2026 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data