diff --git a/libavcodec/pgssubdec.c b/libavcodec/pgssubdec.c
index 1cafd9f832..6217c406d9 100644
--- a/libavcodec/pgssubdec.c
+++ b/libavcodec/pgssubdec.c
@@ -275,6 +275,13 @@ static int parse_object_segment(AVCodecContext *avctx,
     /* Decode rle bitmap length, stored size includes width/height data */
     rle_bitmap_len = bytestream_get_be24(&buf) - 2*2;
 
+    if (buf_size > rle_bitmap_len) {
+        av_log(avctx, AV_LOG_ERROR,
+               "Buffer dimension %d larger than the expected RLE data %d\n",
+               buf_size, rle_bitmap_len);
+        return AVERROR_INVALIDDATA;
+    }
+
     /* Get bitmap dimensions from data */
     width  = bytestream_get_be16(&buf);
     height = bytestream_get_be16(&buf);