projectdiscovery/nuclei · error

validation failed for these fields

Error message

validation failed for these fields

What it means

After YAML decoding, the wrapper (pkg/utils/yaml/yaml_decode_wrapper.go:171) runs go-playground/validator's validate.Struct and collects every violation as `Namespace(): Tag()` pairs, wrapped as 'validation failed for these fields'. The YAML parsed successfully; one or more struct `validate` tags (required, oneof, min, etc.) were violated. The namespaces in the message name the exact failing field paths and the tag that failed.

Source

Thrown at pkg/utils/yaml/yaml_decode_wrapper.go:171

// DecodeAndValidate is a wrapper for yaml Decode adding struct validation
func DecodeAndValidate(r io.Reader, v interface{}) error {
	if err := NewDecoder(r).Decode(v); err != nil {
		return err
	}
	if validate == nil {
		validate = validator.New()
	}

	if err := validate.Struct(v); err != nil {
		if _, ok := err.(*validator.InvalidValidationError); ok {
			return err
		}
		errs := []string{}
		for _, err := range err.(validator.ValidationErrors) {
			errs = append(errs, err.Namespace()+": "+err.Tag())
		}
		return errors.Wrap(errors.New(strings.Join(errs, ", ")), "validation failed for these fields")
	}
	return nil
}

func normalizeDupMappingKeys(node *yaml.Node) {
	node = unwrapDoc(node)
	if node == nil {
		return
	}

	switch node.Kind {
	case yaml.DocumentNode:
		for _, child := range node.Content {
			normalizeDupMappingKeys(child)
		}
	case yaml.SequenceNode:
		for _, child := range node.Content {
			normalizeDupMappingKeys(child)

View on GitHub (pinned to 265b3a3dec)

Solutions

1. Read the namespace list — each entry names the failing field path and the failed tag
2. Fix the named field (e.g. set the enum value to one of the allowed choices)
3. Run `nuclei -validate` to catch violations before scanning
4. Re-validate existing template sets after nuclei upgrades

if err := yaml.DecodeStrict(bytes.NewReader(data), &v); err != nil {
    var vErrs validator.ValidationErrors
    if errors.As(err, &vErrs) {
        for _, fe := range vErrs {
            log.Printf("field %s failed %s", fe.Namespace(), fe.Tag())
        }
    }
    return err
}

When it happens

Trigger: Decoding a template/config struct through the yaml decode wrapper where a required field is empty, an enum (oneof) field holds an out-of-list value, or a numeric min/max/dive constraint fails.

Common situations: Templates missing required info fields or with typo'd enum values (e.g. severity); schema drift after upgrading nuclei adds new validate tags to old templates; hand-built config structs decoded with the wrapper.

Related errors

• Invalid protocol type: {valueToMap}
• invalid workflow with no templates or tags
• include directive preprocessing is disabled
• could not parse profile YAML: %w
• could not marshal inline secrets: %w

AI-assisted analysis of projectdiscovery/nuclei@265b3a3dec (2026-08-15). Data as JSON: /api/errors/68867811d37c9928. Report an issue: GitHub.