diff --git a/lib_com/options.h b/lib_com/options.h
old mode 100644
new mode 100755
index 0e4e064ab7ab3ff96f7bd1869549642bc21dd050..5628bc1331dd841c9bdd5b5928ec01ac683e7054
--- a/lib_com/options.h
+++ b/lib_com/options.h
@@ -205,6 +205,7 @@
 #define FIX617_UBSAN_DIVBYZERO_STEREOCNG                /* Eri: Issue 617: Decoder UBSAN: division by zero in stereo cng when inut is 16kHz and output is 32kHz */
 #define FIX_279_CODE_COVERAGE                           /* Dlb : issue 279 , clean up unused function */
 #define FIX_549_PARAM_ISM_BIN_GAIN                      /* FhG: Issue 549 : fix too quiet binaural output in ParamISM */
+#define FIX_625_IDX_OOB                                 /* FhG: Fix index out-of-bounds UBSAN error (issue 625) */
 
 /* ################## End BE DEVELOPMENT switches ######################### */
 
diff --git a/lib_dec/ivas_spar_decoder.c b/lib_dec/ivas_spar_decoder.c
old mode 100644
new mode 100755
index 1c839316e52fefb4ad4f4e44bc7d7533cd95efe8..195bf57dfb14c87cf8babca5e76b6acc03636562
--- a/lib_dec/ivas_spar_decoder.c
+++ b/lib_dec/ivas_spar_decoder.c
@@ -1019,14 +1019,22 @@ static void ivas_spar_calc_smooth_facs(
     bin = 0;
     for ( b = 0; b < nbands_spar; b++ )
     {
+#ifdef FIX_625_IDX_OOB
+        if ( bin >= CLDFB_NO_CHANNELS_MAX || ( b > 0 && bin2band->p_cldfb_map_to_spar_band[bin] < bin2band->p_cldfb_map_to_spar_band[bin - 1] ) )
+#else
         if ( b > 0 && bin2band->p_cldfb_map_to_spar_band[bin] < bin2band->p_cldfb_map_to_spar_band[bin - 1] )
+#endif
         {
             break;
         }
 
         /* calculate band-wise subframe energies */
         subframe_band_nrg[b] = 0.f;
+#ifdef FIX_625_IDX_OOB
+        while ( bin < CLDFB_NO_CHANNELS_MAX && b == bin2band->p_cldfb_map_to_spar_band[bin] )
+#else
         while ( b == bin2band->p_cldfb_map_to_spar_band[bin] )
+#endif
         {
             for ( ts = 0; ts < MAX_PARAM_SPATIAL_SUBFRAMES; ts++ )
             {