Vol. I · Fri, 2 Oct 2026Open 24 hours · Feeding: continuous · Please do not tap the glass
Plate LXXXIII0x243F0D21UNREAD
Kingdom Automata›Phylum HTTP›Order Scanners›Family Unidentified›Species Nuclei
Specimen file · The Feral Pit

Nuclei

Nucleus vulnerabilis

What is Nuclei?

Nuclei, an open-source vulnerability scanner, testing the site against a list of known weaknesses. It is operated by Unknown and identifies itself as Nuclei.

Temperament: thorough. Arrives with a checklist of thousands of problems. Ticks "not applicable" a great deal.

Operator
Unknown
Conservation status
Has not read the rules
First seen
Not yet
Last seen
Not yet
Visits today
0
This week
0
All time
0
Caught in the trap
Never
How to block Nuclei ↓
§ I.

Identification

Its full user-agent string, exactly as it arrives at the gate:

User-Agent
$ Nuclei - Open-source project (github.com/projectdiscovery/nuclei)

There is no operator to verify against. This name is what software calls itself when nobody gave it one.

§ II.

How to block Nuclei

Nuclei does not read robots.txt, so a polite sign is wasted on it. Refuse it at your web server or firewall instead. User agents are easy to fake, so pair this with rate limiting.

nginx.conf
# robots.txt will not stop Nuclei. Block it at the server.
# nginx
if ($http_user_agent ~* "Nuclei") {
    return 403;
}

The same thing on Apache:

# Apache (.htaccess)
RewriteEngine On
RewriteCond %{HTTP_USER_AGENT} Nuclei [NC]
RewriteRule .* - [F,L]
§ III.

Observed behaviour

Visits, last 30 dayspeak 1 / day
3 Sept 2026today
Diet · pages most often eaten

Nothing on record in the last 30 days.

Visiting hours
00h – 11h12h – 23h
robots.txt compliance
100.0%

Requested 0 disallowed pages out of 0 requests. Never read robots.txt.

Trap Room record
Clean

Has never followed the hidden link to /trap/. Either well trained or very lucky.

§ IV.

Where it comes from

Scripts and scanners run from wherever their owners rent a server. These are the networks behind the visits on file:

Nothing on record in the last 30 days.

Networks and countries come from the visitor's IP address, looked up in a local copy of the DB-IP database. The addresses themselves are never stored.

§ V.

Questions site owners ask

Does Nuclei respect robots.txt?

We can't say yet. It has not fetched robots.txt here, and it has not touched a disallowed page either.

Will blocking Nuclei hurt my search rankings?

No. Nothing respectable will miss it.

How often does Nuclei visit?

Here, about 0 requests a day over the last week. Visits to your site depend on its size, how often it changes, and how many links point to it.

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