diff --git a/libavcodec/vc1.c b/libavcodec/vc1.c
index f88c83d7e4..86f72f32f4 100644
--- a/libavcodec/vc1.c
+++ b/libavcodec/vc1.c
@@ -676,6 +676,8 @@ int ff_vc1_parse_frame_header(VC1Context *v, GetBitContext* gb)
     if (v->s.pict_type == AV_PICTURE_TYPE_P)
         v->rnd ^= 1;
 
+    if (get_bits_left(gb) < 5)
+        return AVERROR_INVALIDDATA;
     /* Quantizer stuff */
     pqindex = get_bits(gb, 5);
     if (!pqindex)
@@ -768,6 +770,9 @@ int ff_vc1_parse_frame_header(VC1Context *v, GetBitContext* gb)
         av_log(v->s.avctx, AV_LOG_DEBUG, "MB Skip plane encoding: "
                "Imode: %i, Invert: %i\n", status>>1, status&1);
 
+        if (get_bits_left(gb) < 4)
+            return AVERROR_INVALIDDATA;
+
         /* Hopefully this is correct for P-frames */
         v->s.mv_table_index = get_bits(gb, 2); //but using ff_vc1_ tables
         v->cbpcy_vlc = &ff_vc1_cbpcy_p_vlc[get_bits(gb, 2)];