diff --git a/resources/web/model/model.js b/resources/web/model/model.js
index b401bea75b..a6918d15d2 100644
--- a/resources/web/model/model.js
+++ b/resources/web/model/model.js
@@ -214,9 +214,9 @@ function ShowModelInfo( pModel )
 	
 	SendWXDebugInfo("Model Name:  "+sModelName);
 	
-	$('#ModelName').html(sModelName);
+	$('#ModelName').text(sModelName);
 	$('#ModelName').attr('title',sModelName);
-    $('#ModelAuthorName').html(sModelAuthor);
+    $('#ModelAuthorName').text(sModelAuthor);
 	
 	switch(UploadType)
 	{
@@ -268,7 +268,7 @@ function ShowModelInfo( pModel )
 			break;
 	}
 	
-	$('#Model_Desc').html( html_decode(sModelDesc) );
+	$('#Model_Desc').empty().append( SanitizeDescHtml( html_decode(sModelDesc) ) );
 			
 	let ModelPreviewList=pModel.preview_img;				
     let TotalPreview=ModelPreviewList.length;
@@ -410,7 +410,8 @@ function ConstructFileHtml( ID, pItem )
 {
 	let fTotal=pItem.length;
 	
-	let strHtml='';
+	let pBoard=$('#'+ID+'  .FileListBoard');
+	pBoard.empty();
 	for( let f=0;f<fTotal;f++ )
 	{
 		let pOne=pItem[f];
@@ -443,39 +444,92 @@ function ConstructFileHtml( ID, pItem )
 			ImgPath='img/default.png';			
 		}		
 			
-		//Add html
+		//Add html. File names come from the 3MF, so build the nodes rather than concatenating markup.
+		let pIconImg=$('<img />').attr('src',ImgPath);
+		let pMenu=$('<div class="FileMenu"><img src="img/s.svg" /></div>');
 		if( strClass!='ImageIcon' )
 		{
-		strHtml+='<div class="FileItem">'+
-				 '	<div class="'+strClass+'"><img src="'+ImgPath+'" /></div>'+
-				 '	<div class="FileText">'+
-			     '		<div class="FileName">'+tName+'</div>'+
-				 '	</div>'+
-				 '	<div class="FileMenu" onClick="OnClickOpenFile(\''+tPath+'\')"><img src="img/s.svg" /></div>'+
-				 '</div>';
+			pMenu.on('click', function(){ OnClickOpenFile(tPath); });
 		}
 		else
 		{
 			ImgID++;
 			let TmpImgID="AF"+ImgID;
 			
-		strHtml+='<div class="FileItem">'+
-				 '	<div class="'+strClass+'"><img id="'+TmpImgID+'" src="'+ImgPath+'" /></div>'+
-				 '	<div class="FileText">'+
-			     '		<div class="FileName">'+tName+'</div>'+
-				 '	</div>'+
-				 '	<div class="FileMenu" onClick="OnClickOpenImage(\''+TmpImgID+'\')"><img src="img/s.svg" /></div>'+
-				 '</div>';			
+			pIconImg.attr('id',TmpImgID);
+			pMenu.on('click', function(){ OnClickOpenImage(TmpImgID); });
 		}
+		
+		let pFileItem=$('<div class="FileItem"></div>');
+		pFileItem.append( $('<div></div>').addClass(strClass).append(pIconImg) );
+		pFileItem.append( $('<div class="FileText"></div>').append( $('<div class="FileName"></div>').text(tName) ) );
+		pFileItem.append( pMenu );
+		pBoard.append( pFileItem );
 	}
 	
-	$('#'+ID+'  .FileListBoard').html(strHtml);
-	
     if( fTotal>0 )
 		$('#'+ID).show();
 }
 
 
+// Descriptions are untrusted 3MF metadata that may carry rich-text HTML (e.g. from MakerWorld).
+// Rebuild them from an inert parse, keeping only plain formatting tags and http(s) links and images.
+var DescAllowedTags=['P','BR','B','STRONG','I','EM','U','S','STRIKE','SUB','SUP','SMALL','MARK',
+	'H1','H2','H3','H4','H5','H6','UL','OL','LI','BLOCKQUOTE','PRE','CODE','HR','SPAN','DIV',
+	'TABLE','THEAD','TBODY','TFOOT','TR','TH','TD','A','IMG'];
+// Dropped together with their content; any other unknown tag is unwrapped to its children.
+var DescDroppedTags=['SCRIPT','STYLE','TEMPLATE','NOSCRIPT','TEXTAREA','TITLE','IFRAME','FRAME','OBJECT','EMBED','SVG','MATH'];
+
+function IsHttpUrl( strUrl )
+{
+	return /^\s*https?:\/\//i.test(strUrl||'');
+}
+
+function CopyDescNodes( pSrc, pDst )
+{
+	for( let pNode=pSrc.firstChild;pNode!=null;pNode=pNode.nextSibling )
+	{
+		if( pNode.nodeType==Node.TEXT_NODE )
+		{
+			pDst.appendChild( document.createTextNode(pNode.nodeValue) );
+			continue;
+		}
+		if( pNode.nodeType!=Node.ELEMENT_NODE )
+			continue;
+		
+		let sTag=pNode.nodeName.toUpperCase();
+		if( $.inArray(sTag,DescDroppedTags)>=0 )
+			continue;
+		if( $.inArray(sTag,DescAllowedTags)<0 )
+		{
+			CopyDescNodes(pNode,pDst);
+			continue;
+		}
+		
+		let pElem=document.createElement(sTag);
+		if( sTag=='A' && IsHttpUrl(pNode.getAttribute('href')) )
+			pElem.setAttribute('href',pNode.getAttribute('href'));
+		else if( sTag=='IMG' )
+		{
+			if( !IsHttpUrl(pNode.getAttribute('src')) )
+				continue;
+			pElem.setAttribute('src',pNode.getAttribute('src'));
+		}
+		CopyDescNodes(pNode,pElem);
+		pDst.appendChild(pElem);
+	}
+}
+
+function SanitizeDescHtml( strHtml )
+{
+	let pFragment=document.createDocumentFragment();
+	// A DOMParser document is inert: it runs no scripts and loads no resources.
+	let pDoc=new DOMParser().parseFromString(strHtml,'text/html');
+	if( pDoc && pDoc.body )
+		CopyDescNodes(pDoc.body,pFragment);
+	return pFragment;
+}
+
 function ShowProfilelInfo( pProfile )
 {
 	//==========Profile Info==========
@@ -483,10 +537,10 @@ function ShowProfilelInfo( pProfile )
 	let sProfileAuthor=decodeURIComponent(pProfile.author);
 	let sProfileDesc=decodeURIComponent(pProfile.description);
 	
-	$('#ProfileName').html(sProfileName);
-    $('#ProfileAuthor').html(sProfileAuthor);
+	$('#ProfileName').text(sProfileName);
+    $('#ProfileAuthor').text(sProfileAuthor);
 		
-	$('#Profile_Desc').html( html_decode(sProfileDesc) );
+	$('#Profile_Desc').empty().append( SanitizeDescHtml( html_decode(sProfileDesc) ) );
 			
 	let ProfilePreviewList=pProfile.preview_img;				
     let TotalPreview=ProfilePreviewList.length;
diff --git a/src/libslic3r/Utils.hpp b/src/libslic3r/Utils.hpp
index eff7f51c2a..d4062e07b1 100644
--- a/src/libslic3r/Utils.hpp
+++ b/src/libslic3r/Utils.hpp
@@ -263,6 +263,9 @@ extern bool is_path_within_root(const std::string &rel_path, const boost::filesy
 // True if a symlink stored at link_rel_path (relative to root) with this target stays inside root: the target
 // must be relative, and joined to the link's directory it must pass is_path_within_root.
 extern bool is_symlink_target_within_root(const std::string &link_rel_path, const std::string &target, const boost::filesystem::path &root);
+// True if path names an entry strictly inside root: it must be spelled with root as its prefix,
+// and must still resolve inside root once symlinks are followed.
+extern bool is_absolute_path_within_root(const boost::filesystem::path &path, const boost::filesystem::path &root);
 
 // Orca: custom protocal support utils
 inline bool is_orca_open(const std::string& url) { return boost::starts_with(url, "orcaslicer://open"); }
diff --git a/src/libslic3r/utils.cpp b/src/libslic3r/utils.cpp
index 303476f023..5e795438f1 100644
--- a/src/libslic3r/utils.cpp
+++ b/src/libslic3r/utils.cpp
@@ -1127,6 +1127,12 @@ bool is_symlink_target_within_root(const std::string &link_rel_path, const std::
     return is_path_within_root((sep == std::string::npos ? std::string() : link_rel_path.substr(0, sep + 1)) + target, root);
 }
 
+bool is_absolute_path_within_root(const boost::filesystem::path &path, const boost::filesystem::path &root)
+{
+    const boost::filesystem::path rel = path.lexically_relative(root);
+    return !rel.empty() && rel != "." && is_path_within_root(rel.string(), root);
+}
+
 bool is_img_file(const std::string &path)
 {
 	return boost::iends_with(path, ".png") || boost::iends_with(path, ".svg");
diff --git a/src/slic3r/GUI/Project.cpp b/src/slic3r/GUI/Project.cpp
index 7833cc7499..1ccb269f51 100644
--- a/src/slic3r/GUI/Project.cpp
+++ b/src/slic3r/GUI/Project.cpp
@@ -293,9 +293,13 @@ void ProjectPanel::OnScriptMessage(wxWebViewEvent& evt)
             if (!accessory_path.empty()) {
                 std::string decode_path = wxGetApp().url_decode(accessory_path.ToStdString());
                 fs::path path(decode_path);
+                // Only open the project's own extracted auxiliary files, with the root built as in Reload().
+                fs::path aux_root(encode_path(wxGetApp().plater()->model().get_auxiliary_file_temp_path().c_str()));
 
-                if (fs::exists(path)) {
+                if (is_absolute_path_within_root(path, aux_root) && fs::is_regular_file(path)) {
                     wxLaunchDefaultApplication(path.wstring(), 0);
+                } else {
+                    BOOST_LOG_TRIVIAL(warning) << "open_3mf_accessory: ignoring path outside the project auxiliary directory: " << decode_path;
                 }
             }
         }
diff --git a/tests/libslic3r/test_utils.cpp b/tests/libslic3r/test_utils.cpp
index e2b220d482..ca5d9e07fc 100644
--- a/tests/libslic3r/test_utils.cpp
+++ b/tests/libslic3r/test_utils.cpp
@@ -322,3 +322,48 @@ TEST_CASE("is_symlink_target_within_root rejects a target that passes through a
     CHECK(is_symlink_target_within_root("link", "in/lib.so", root));
 }
 #endif
+
+TEST_CASE("is_absolute_path_within_root accepts only entries inside the root", "[utils]") {
+    namespace fs = boost::filesystem;
+    ScopedTemporaryDir outer;
+    const fs::path root = outer.path() / "Auxiliaries";
+    fs::create_directories(root / "Others");
+    const fs::path inside = root / "Others" / "note.txt";
+    const fs::path outside = outer.path() / "secret.txt";
+    std::ofstream(inside.string()) << "inside";
+    std::ofstream(outside.string()) << "outside";
+
+    SECTION("a file inside the root") {
+        REQUIRE(is_absolute_path_within_root(inside, root));
+    }
+    SECTION("a path inside the root whose file does not exist yet") {
+        REQUIRE(is_absolute_path_within_root(root / "Others" / "missing.txt", root));
+    }
+    SECTION("the root itself") {
+        REQUIRE_FALSE(is_absolute_path_within_root(root, root));
+    }
+    SECTION("a parent-directory escape spelled under the root") {
+        REQUIRE_FALSE(is_absolute_path_within_root(root / "Others" / ".." / ".." / "secret.txt", root));
+    }
+    SECTION("an absolute path elsewhere") {
+        REQUIRE_FALSE(is_absolute_path_within_root(outside, root));
+    }
+    SECTION("a sibling directory sharing the root's name as a prefix") {
+        const fs::path sibling = outer.path() / "Auxiliaries2" / "note.txt";
+        REQUIRE_FALSE(is_absolute_path_within_root(sibling, root));
+    }
+    SECTION("a relative path") {
+        REQUIRE_FALSE(is_absolute_path_within_root(fs::path("Others") / "note.txt", root));
+    }
+    SECTION("an empty path") {
+        REQUIRE_FALSE(is_absolute_path_within_root(fs::path(), root));
+    }
+#ifndef _WIN32
+    // Creating symlinks on Windows needs elevated rights or developer mode.
+    SECTION("a symlink inside the root that points outside") {
+        const fs::path link = root / "Others" / "link.txt";
+        fs::create_symlink(outside, link);
+        REQUIRE_FALSE(is_absolute_path_within_root(link, root));
+    }
+#endif
+}