Nuclei stops early?

[carstenfuchs]

Hello,

we've been developing a web application (based on the Django framework) and I'm now trying to run Nuclei against it (on Ubuntu 24.04 LTS).

However, when running Nuclei, the scan appears to abort early: only ~115 out of 5471 planned requests are executed, after which (or even after only 65?) the target is marked as permanently unresponsive and the scan finishes.

Please consider the following output:

$ ~/go/bin/nuclei -u https://lori.example.de -tags misconfig,exposure,django,apache -timeout 10 -retries 2 -no-interactsh -stats

                     __     _
   ____  __  _______/ /__  (_)
  / __ \/ / / / ___/ / _ \/ /
 / / / / /_/ / /__/ /  __/ /
/_/ /_/\__,_/\___/_/\___/_/   v3.7.0

                projectdiscovery.io

[WRN] Found 1 templates with runtime error (use -validate flag for further examination)
[INF] Current nuclei version: v3.7.0 (latest)
[INF] Current nuclei-templates version: v10.3.8 (latest)
[INF] New templates added in latest release: 457
[INF] Templates loaded for current scan: 2042
[INF] Executing 2042 signed templates from projectdiscovery/nuclei-templates
[INF] Targets loaded for current scan: 1
[INF] Templates clustered: 576 (Reduced 537 Requests)
[0:00:05] | Templates: 2042 | Hosts: 1 | RPS: 3 | Matched: 0 | Errors: 0 | Requests: 21/5471 (0%)
[0:00:10] | Templates: 2042 | Hosts: 1 | RPS: 2 | Matched: 0 | Errors: 0 | Requests: 21/5471 (0%)
[0:00:15] | Templates: 2042 | Hosts: 1 | RPS: 2 | Matched: 0 | Errors: 0 | Requests: 37/5471 (0%)
[0:00:20] | Templates: 2042 | Hosts: 1 | RPS: 1 | Matched: 0 | Errors: 0 | Requests: 37/5471 (0%)
[0:00:25] | Templates: 2042 | Hosts: 1 | RPS: 1 | Matched: 0 | Errors: 0 | Requests: 45/5471 (0%)
[0:00:30] | Templates: 2042 | Hosts: 1 | RPS: 1 | Matched: 0 | Errors: 0 | Requests: 45/5471 (0%)
[0:00:35] | Templates: 2042 | Hosts: 1 | RPS: 1 | Matched: 0 | Errors: 9 | Requests: 65/5471 (1%)
[0:00:40] | Templates: 2042 | Hosts: 1 | RPS: 1 | Matched: 0 | Errors: 9 | Requests: 65/5471 (1%)
[INF] Skipped lori.example.de:443 from target list as found unresponsive permanently: cause="i/o timeout" address=lori.example.de:443
[0:00:45] | Templates: 2042 | Hosts: 1 | RPS: 2 | Matched: 0 | Errors: 29 | Requests: 95/5471 (1%)
[0:00:50] | Templates: 2042 | Hosts: 1 | RPS: 2 | Matched: 0 | Errors: 29 | Requests: 112/5471 (2%)
[0:00:51] | Templates: 2042 | Hosts: 1 | RPS: 2 | Matched: 0 | Errors: 29 | Requests: 115/5471 (2%)
[INF] Scan completed in 50.687192197s. 0 matches found.
[0:00:51] | Templates: 2042 | Hosts: 1 | RPS: 2 | Matched: 0 | Errors: 29 | Requests: 115/5471 (2%)

$

This is the complete output, not a clipped copy & paste.

Is this expected behavior or am I doing something wrong? In particular, I would like to understand why the host is marked as permanently unresponsive so early. The output is similar if I vary the timeout and retries settings, even to large values.

Thanks!