Valid extension for nuclei template file?

[locaIhost]

Is there an existing issue for this?

• I have searched the existing issues.

Current Behavior

When I try to run Nuclei with a template file that has a .yml extension, the tool doesn’t recognize it as a valid YAML template. Instead, it misinterprets the file’s content (like id: template-name) as a list of template IDs or file paths. This leads to an error like:

Expected Behavior

Nuclei should treat files with both .yaml and .yml extensions as valid YAML templates since they’re standard and synonymous for YAML files. When I run nuclei -t template.yml, the tool should parse the file as a YAML template and execute it properly, without misinterpreting its content.

Steps To Reproduce

1. Create a file named test.yml with this content:

---
id: test-template
info:
  name: Test Template
  author: test
  severity: info
requests:
  - method: GET
    path:
      - "{{Host}}"

2. Run nuclei -t ./test.yaml -u example.com --debug
3. You’ll see this error:

[ERR] Could not find template 'id: test-template': could not find file: open /path/to/templates/id: test-template: no such file or directory

4. For comparison, rename the file to test.yaml and try again:

mv test.yml test.yaml
nuclei -t ./test.yaml -u example.com

Relevant log output

[VER] Started metrics server at localhost:9092
[ERR] Could not find template '      - "{{Host}}"': could not find file: open /root/nuclei-templates/      - "{{Host}}": no such file or directory
[ERR] Could not find template 'id: test-template': could not find file: open /root/nuclei-templates/id: test-template: no such file or directory
[ERR] Could not find template '  severity: info': could not find file: open /root/nuclei-templates/  severity: info: no such file or directory
[ERR] Could not find template 'requests:': could not find file: open /root/nuclei-templates/requests:: no such file or directory
[ERR] Could not find template '    path:': could not find file: open /root/nuclei-templates/    path:: no such file or directory
[ERR] Could not find template 'info:': could not find file: open /root/nuclei-templates/info:: no such file or directory
[ERR] Could not find template '  name: Test Template': could not find file: open /root/nuclei-templates/  name: Test Template: no such file or directory
[ERR] Could not find template '  author: test': could not find file: open /root/nuclei-templates/  author: test: no such file or directory
[ERR] Could not find template '  - method: GET': could not find file: open /root/nuclei-templates/  - method: GET: no such file or directory
[INF] Current nuclei version: v3.4.3 (latest)
[INF] Current nuclei-templates version: v10.2.0 (latest)
[WRN] Scan results upload to cloud is disabled.
[INF] Targets loaded for current scan: 1
[INF] Scan completed in 997.182µs. No results found.
[FTL] Could not run nuclei: no templates provided for scan

Environment

- OS: MacOS 15.4.1 / Fedora Linux 42
- Nuclei: v3.4.3
- Go: go1.24.2 /

Anything else?

If there is a ticket with this problem, just close this issue. 🐰

[ehsandeep]

To avoid nuclei parsing all types of config files on the system or from GitHub in .yml format.

Nuclei specifically recognizes .yaml files for templates.

See #6214 (comment)