## TL;DR
Stale plugin warnings mean the scanner's checks may miss recent vulnerabilities and mislabel old ones, so results should not ship until the feed is current. Run the feed update, fix the usual blockers, registration, proxy, or a wrong system clock, and confirm the plugin set date in the scanner before rescanning the authorized targets.

```text
nessus plugin feed out of date warning on authorized scan
```

## Use this when
- Nessus shows a plugin feed out of date or plugins last updated long ago banner.
- Feed update attempts fail or appear to succeed without changing the plugin date.

## Not for this skill when
- The feed is current but a scan still errors. Leave the feed alone and debug the scan.
- The scanner is air-gapped by design. Use the offline feed procedure agreed for that environment instead of chasing internet access.

## Steps
1. Record the plugin set date Nessus reports now, and check the tester box system clock against a known good time source. Verify: Verify: you have the stale date written down and the clock is either right or identified as the blocker.
2. Confirm the scanner registration is active in its settings; an expired or transferred licence quietly stops feed updates. Verify: Verify: registration shows active for this scanner.
3. Run the plugin feed update from the Nessus interface or its command line update tool, watching for proxy or connectivity errors. Verify: Verify: the update completes and downloads a current plugin archive.
4. If the box sits behind a proxy, set the Nessus proxy settings explicitly rather than relying on browser settings, and retry the update. Verify: Verify: the update log shows the feed host reached through the proxy.
5. Restart the Nessus service if prompted, confirm the plugin date is now current, and note the feed date in the engagement record for the scan about to run. Verify: Verify: the warning is gone and the recorded date matches the scanner display.

## Variant phrasings
### nessus update plugins command line feed update fails
The update-mechanics phrasing.
### nessus plugin feed stale proxy registration expired
The blocker phrasing.
### nessus offline feed update air gapped scanner
The offline phrasing for closed environments.

Compatibility: Compatibility: Tenable Nessus Professional and Expert; feed mechanics differ for scanners managed through Tenable.io or Security Center.

## Why it happens
Nessus detection quality is its plugin feed: new checks and fixes arrive continuously, and the scanner warns when its set ages because findings would silently skew. Updates fail for mundane infrastructure reasons, licence state, proxies the service account cannot use, or a clock far enough off to break TLS and feed signing checks.

## Edge cases / pitfalls
- Do not deliver a report from a stale-feed scan without disclosing the feed date; clients and retest comparisons depend on it.
- A feed update mid-engagement changes detection between the original scan and a retest; note both feed dates when comparing.
- Offline environments need the feed staged through approved media; never bridge an air gap ad hoc to fetch plugins.

## Provenance

Resolved from the public thread: https://vectle.com/posts/pst_rHX7RsS1kKQfY-xVgyCy8Q