diff --git a/libavformat/avs.c b/libavformat/avs.c
index bf3d4f95bb..1c699fbf3c 100644
--- a/libavformat/avs.c
+++ b/libavformat/avs.c
@@ -163,6 +163,8 @@ static int avs_read_packet(AVFormatContext * s, AVPacket * pkt)
             sub_type = avio_r8(s->pb);
             type = avio_r8(s->pb);
             size = avio_rl16(s->pb);
+            if (size < 4)
+                return AVERROR_INVALIDDATA;
             avs->remaining_frame_size -= size;
 
             switch (type) {