diff --git a/libavcodec/c93.c b/libavcodec/c93.c
index e5f371b081..c6358d5b5c 100644
--- a/libavcodec/c93.c
+++ b/libavcodec/c93.c
@@ -175,7 +175,13 @@ static int decode_frame(AVCodecContext *avctx, void *data,
             case C93_4X4_FROM_PREV:
                 for (j = 0; j < 8; j += 4) {
                     for (i = 0; i < 8; i += 4) {
-                        offset = bytestream2_get_le16(&gb);
+                        int offset = bytestream2_get_le16(&gb);
+                        int from_x = offset % WIDTH;
+                        int from_y = offset / WIDTH;
+                        if (block_type == C93_4X4_FROM_CURR && from_y == y+j &&
+                            (FFABS(from_x - x-i) < 4 || FFABS(from_x - x-i) > WIDTH-4)) {
+                            return AVERROR_INVALIDDATA;
+                        }
                         if ((ret = copy_block(avctx, &out[j*stride+i],
                                               copy_from, offset, 4, stride)) < 0)
                             return ret;