feat: fixed bug due to parallel auto setting in http (#4992)

* feat: fixed bug due to parallel auto setting in http

* increased threshold

---------

Co-authored-by: sandeep <8293321+ehsandeep@users.noreply.github.com>

pkg/protocols/http/http.go

@@ -20,6 +20,7 @@ import (
 	httputil "github.com/projectdiscovery/nuclei/v3/pkg/protocols/utils/http"
 	"github.com/projectdiscovery/rawhttp"
 	"github.com/projectdiscovery/retryablehttp-go"
+	"github.com/projectdiscovery/utils/env"
 	fileutil "github.com/projectdiscovery/utils/file"
 )
 
@@ -440,7 +441,11 @@ func (request *Request) Compile(options *protocols.ExecutorOptions) error {
 			request.Threads = protocolstate.GuardThreadsOrDefault(request.Threads)
 		}
 		// if we have payloads, adjust threads if none specified
-		request.Threads = options.GetThreadsForNPayloadRequests(request.Requests(), request.Threads)
+		// We only do this in case we have more payload requests than the
+		// specified concurrency threshold.
+		if request.generator.NewIterator().Total() > PayloadAutoConcurrencyThreshold {
+			request.Threads = options.GetThreadsForNPayloadRequests(request.Requests(), request.Threads)
+		}
 	}
 
 	return nil
@@ -467,3 +472,11 @@ func (request *Request) Requests() int {
 	}
 	return len(request.Path)
 }
+
+// PayloadAutoConcurrencyThreshold is the threshold for auto adjusting concurrency
+// for payloads in a template.
+var PayloadAutoConcurrencyThreshold int
+
+func init() {
+	PayloadAutoConcurrencyThreshold = env.GetEnvOrDefault[int]("NUCLEI_PAYLOAD_AUTO_CONCURRENCY_THRESHOLD", 100)
+}