diff --git a/libavformat/matroskadec.c b/libavformat/matroskadec.c
index 4582fb59b7..53e02d8748 100644
--- a/libavformat/matroskadec.c
+++ b/libavformat/matroskadec.c
@@ -4085,7 +4085,7 @@ static int64_t webm_dash_manifest_compute_bandwidth(AVFormatContext *s, int64_t
                 int64_t desc_bytes = desc_end.end_offset - desc_beg.start_offset;
                 int64_t desc_ns = desc_end.end_time_ns - desc_beg.start_time_ns;
                 double desc_sec, calc_bits_per_second, percent, mod_bits_per_second;
-                if (desc_bytes <= 0)
+                if (desc_bytes <= 0 || desc_bytes > INT64_MAX/8)
                     return -1;
 
                 desc_sec = desc_ns / nano_seconds_per_second;