@@ -0,0 +1,56 @@
+package handler
+
+import (
+	"context"
+	"encoding/hex"
+	"net"
+	"testing"
+
+	"github.com/rs/zerolog"
+	"go.opentelemetry.io/otel/trace/noop"
+	"golang.org/x/crypto/bcrypt"
+
+	"github.com/glauth/glauth/v2/pkg/config"
+	"github.com/glauth/ldap"
+)
+
+func TestConfigBackendDisabledUserCannotBind(t *testing.T) {
+	pw := "correct horse"
+	raw, _ := bcrypt.GenerateFromPassword([]byte(pw), bcrypt.MinCost)
+	hexHash := hex.EncodeToString(raw)
+
+	cfg := &config.Config{}
+	cfg.Users = []config.User{
+		{Name: "activeuser", PrimaryGroup: 5501, PassBcrypt: hexHash, Disabled: false},
+		{Name: "disableduser", PrimaryGroup: 5501, PassBcrypt: hexHash, Disabled: true},
+	}
+
+	logger := zerolog.Nop()
+	tracer := noop.NewTracerProvider().Tracer("f001")
+	helper := NewLDAPOpsHelper(tracer)
+	h := configHandler{
+		backend: config.Backend{
+			BaseDN:             "dc=example,dc=com",
+			NameFormatAsArray:  []string{"cn"},
+			GroupFormatAsArray: []string{"ou"},
+		},
+		log:       &logger,
+		cfg:       cfg,
+		ldohelper: helper,
+		tracer:    tracer,
+	}
+	_, server := net.Pipe()
+	defer server.Close()
+
+	bind := func(dn, pass string) ldap.LDAPResultCode {
+		code, _ := helper.Bind(context.Background(), h, dn, pass, server)
+		return code
+	}
+
+	if code := bind("cn=activeuser,dc=example,dc=com", pw); code != ldap.LDAPResultSuccess {
+		t.Fatalf("active user with correct pw should bind, got %d", code)
+	}
+	if code := bind("cn=disableduser,dc=example,dc=com", pw); code != ldap.LDAPResultInvalidCredentials {
+		t.Errorf("disabled user must be rejected; got code %d, want InvalidCredentials(49)", code)
+	}
+}
@@ -102,6 +102,12 @@ func (l LDAPOpsHelper) Bind(ctx context.Context, h LDAPOpsHandler, bindDN, bindS
 		return ldapcode, nil
 	}
 
+	// a disabled account must never authenticate, on any backend
+	if user.Disabled {
+		h.GetLog().Info().Str("binddn", bindDN).Str("src", conn.RemoteAddr().String()).Msg("Bind attempt on disabled account")
+		return ldap.LDAPResultInvalidCredentials, nil
+	}
+
 	validotp := false
 
 	if len(user.Yubikey) == 0 && len(user.OTPSecret) == 0 {