diff -urNp a/IlmImf/ImfHeader.cpp b/IlmImf/ImfHeader.cpp
--- a/IlmImf/ImfHeader.cpp	2020-06-02 12:22:29.671798164 +0200
+++ b/IlmImf/ImfHeader.cpp	2020-06-02 12:24:15.802826230 +0200
@@ -708,7 +708,7 @@ Header::sanityCheck (bool isTiled) const
 
 	const TileDescription &tileDesc = tileDescription();
 
-	if (tileDesc.xSize <= 0 || tileDesc.ySize <= 0)
+	if (tileDesc.xSize <= 0 || tileDesc.ySize <= 0 || tileDesc.xSize > INT_MAX || tileDesc.ySize > INT_MAX )
 	    throw Iex::ArgExc ("Invalid tile size in image header.");
 
 	if (maxTileWidth > 0 &&