Downgrade Nessus Software

Nessus 8.10.0 and later supports the ability to downgrade Nessus to a previous version of Nessus. You cannot downgrade to a version before 8.10.0.

You can downgrade Nessus software manually, or, for you can configure the Nessus Update Plan to automatically downgrade to an older release.

Before you begin:

• Tenable recommends that you create a Nessus backup file.

• If Nessus has an encryption password, you cannot downgrade by changing the Nessus update plan. Remove the encryption password from Nessus before you downgrade, then set the encryption password again after the downgrade is complete.

  To remove the Nessus encryption password, see the How to remove the encryption password (formerly master password) through the command-line knowledge base article. To set the Nessus encryption password after downgrading, see Set an Encryption Password.

To downgrade Nessus manually on Linux or macOS:

1. Turn off automatic software updates by doing either of the following:

   • Change your Nessus software update plan as described in Update Nessus Software, set Automatic Updates to Disabled.
   • Modify the advanced setting Automatically Update Nessus (auto_update_ui), as described in Advanced Settings.

2. Use one of the following procedures depending on your operating system:

   Linux

   1. Download the Nessus version you want to install.
   2. Manually install the Nessus version. Force install the new Nessus rpm file over the current rpm file.
   macOS

   1. Download the Nessus version you want to install.
   2. Manually install the Nessus version. Replace the current Nessus pkg file with the new pkg file.

To configure Nessus to downgrade automatically (Nessus Professional, Nessus Expert, and Tenable.io-managed Nessus scanners only):

1. In Nessus, in the top navigation bar, click Settings.

   The About page appears.

2. Click the Software Update tab.

3. Set the Nessus Update Plan to determine what version Nessus automatically updates to. To automatically downgrade, select Delay updates, staying on an older release.

   Note: If you change your update plan and have automatic updates enabled, Nessus may immediately update to align with the version represented by your selected plan. Nessus may either upgrade or downgrade versions.

   Option	Description
   Update to the latest GA release (Default)	Automatically updates to the latest Nessus version when it is made generally available (GA). Note: This date is the same day the version is made generally available.
   Opt in to Early Access releases	Automatically updates to the latest Nessus version as soon as it is released for Early Access (EA), typically a few weeks before general availability.
   Delay updates, staying on an older release	Does not automatically update to the latest Nessus version. Remains on an earlier version of Nessus set by Tenable, usually one release older than the current generally available version, but no earlier than 8.10.0. When Nessus releases a new version, your Nessus instance updates software versions, but stays on a version prior to the latest release.

4. Click the Save button.

   Nessus saves the update plan.