diff --git a/pkg/files/files.go b/pkg/files/files.go
index 8c67c6550..4c8460c8b 100644
--- a/pkg/files/files.go
+++ b/pkg/files/files.go
@@ -37,6 +37,7 @@ import (
 	"github.com/aws/aws-sdk-go-v2/aws"
 	"github.com/aws/aws-sdk-go-v2/service/s3"
 	"github.com/c2h5oh/datasize"
+	"github.com/gabriel-vasile/mimetype"
 	"github.com/spf13/afero"
 	"xorm.io/xorm"
 )
@@ -86,7 +87,14 @@ func (f *File) LoadFileMetaByID() (err error) {
 
 // Create creates a new file from an FileHeader
 func Create(f io.ReadSeeker, realname string, realsize uint64, a web.Auth) (file *File, err error) {
-	return CreateWithMime(f, realname, realsize, a, "")
+	mime, err := mimetype.DetectReader(f)
+	if err != nil {
+		return nil, fmt.Errorf("failed to detect mime type: %w", err)
+	}
+	if _, err := f.Seek(0, io.SeekStart); err != nil {
+		return nil, fmt.Errorf("failed to seek after mime detection: %w", err)
+	}
+	return CreateWithMime(f, realname, realsize, a, mime.String())
 }
 
 // CreateWithMime creates a new file from an FileHeader and sets its mime type
diff --git a/pkg/files/files_test.go b/pkg/files/files_test.go
index 70377fd32..cdaad2f5d 100644
--- a/pkg/files/files_test.go
+++ b/pkg/files/files_test.go
@@ -18,6 +18,8 @@ package files
 
 import (
 	"bytes"
+	"image"
+	"image/png"
 	"os"
 	"testing"
 
@@ -60,6 +62,37 @@ func TestCreate(t *testing.T) {
 	})
 }
 
+func TestCreateDetectsMimeType(t *testing.T) {
+	initFixtures(t)
+	ta := &testauth{id: 1}
+
+	// Minimal valid PNG (1x1 pixel)
+	pngData := createMinimalPNG(t)
+
+	f, err := Create(bytes.NewReader(pngData), "test.png", uint64(len(pngData)), ta)
+	require.NoError(t, err)
+	assert.Equal(t, "image/png", f.Mime)
+}
+
+func TestCreateDetectsMimeTypePlainText(t *testing.T) {
+	initFixtures(t)
+	ta := &testauth{id: 1}
+
+	textData := []byte("hello world this is plain text")
+
+	f, err := Create(bytes.NewReader(textData), "readme.txt", uint64(len(textData)), ta)
+	require.NoError(t, err)
+	assert.Equal(t, "text/plain; charset=utf-8", f.Mime)
+}
+
+func createMinimalPNG(t *testing.T) []byte {
+	t.Helper()
+	img := image.NewRGBA(image.Rect(0, 0, 1, 1))
+	buf := &bytes.Buffer{}
+	require.NoError(t, png.Encode(buf, img))
+	return buf.Bytes()
+}
+
 func TestFile_Delete(t *testing.T) {
 	t.Run("Normal", func(t *testing.T) {
 		s := db.NewSession()
diff --git a/pkg/models/task_attachment_test.go b/pkg/models/task_attachment_test.go
index abdffd029..258c136d4 100644
--- a/pkg/models/task_attachment_test.go
+++ b/pkg/models/task_attachment_test.go
@@ -113,6 +113,7 @@ func TestTaskAttachment_NewAttachment(t *testing.T) {
 	assert.Equal(t, testuser.ID, ta.File.CreatedByID)
 	assert.Equal(t, "testfile", ta.File.Name)
 	assert.Equal(t, uint64(100), ta.File.Size)
+	assert.NotEmpty(t, ta.File.Mime, "mime type should be detected and stored")
 
 	// Extra test for max size test
 }