diff --git a/libavcodec/sheervideo.c b/libavcodec/sheervideo.c
index 2f08b7bff0..5b03ce4431 100644
--- a/libavcodec/sheervideo.c
+++ b/libavcodec/sheervideo.c
@@ -3098,6 +3098,11 @@ static int decode_frame(AVCodecContext *avctx,
         return AVERROR_PATCHWELCOME;
     }
 
+    if (avpkt->size < 20 + avctx->width * avctx->height / 16) {
+        av_log(avctx, AV_LOG_ERROR, "Input packet too small\n");
+        return AVERROR_INVALIDDATA;
+    }
+
     if (s->format != format) {
         if (ret < 0)
             return ret;