diff --git a/lib/docset_renderer.php b/lib/docset_renderer.php
index 032cd21..4a2e9af 100644
--- a/lib/docset_renderer.php
+++ b/lib/docset_renderer.php
@@ -93,7 +93,12 @@ class DocsetRenderer
 		if($value === '' || str_starts_with($value, '#'))
 			return $value;
 		$lower = strtolower($value);
-		foreach(array('http://', 'https://', 'mailto:', 'data:', 'javascript:', 'about:') as $prefix)
+		foreach(array('javascript:', 'vbscript:') as $prefix)
+		{
+			if(str_starts_with($lower, $prefix))
+				return '#blocked-unsafe-url';
+		}
+		foreach(array('http://', 'https://', 'mailto:', 'data:', 'about:') as $prefix)
 		{
 			if(str_starts_with($lower, $prefix))
 				return $value;
diff --git a/tests/smoke.php b/tests/smoke.php
index 4ce5137..3d7b277 100644
--- a/tests/smoke.php
+++ b/tests/smoke.php
@@ -9,6 +9,7 @@ require_once 'lib/ulib.php';
 require_once 'lib/components.php';
 require_once 'lib/theme_helpers.php';
 require_once 'lib/docset_repository.php';
+require_once 'lib/docset_renderer.php';
 
 function assert_true($condition, string $message): void
 {
@@ -30,6 +31,11 @@ $repo = new DocsetRepository();
 $docsets = $repo->listDocsets();
 assert_true(is_array($docsets), 'docset list returns an array');
 
+$sanitized = DocsetRenderer::renderInlineHtml('<main><a href="javascript:alert(1)" onclick="alert(2)">bad link</a></main>', $repo, 'PHP', '.');
+assert_true(!str_contains(strtolower($sanitized), 'javascript:'), 'inline renderer blocks javascript URLs from docset HTML');
+assert_true(!str_contains(strtolower($sanitized), 'onclick='), 'inline renderer strips event handler attributes from docset HTML');
+assert_true(str_contains($sanitized, '#blocked-unsafe-url'), 'inline renderer keeps unsafe links inert and visible');
+
 $phpDocset = $repo->getDocset('PHP');
 if($phpDocset)
 {
@@ -39,7 +45,6 @@ if($phpDocset)
 	assert_true(isset($results[0]['href']), 'search result contains view URL');
 	$doc = $repo->resolveDocumentPath('PHP', 'www.php.net/manual/en/function.array-map.html');
 	assert_true($doc !== null, 'PHP docset document resolves');
-	require_once 'lib/docset_renderer.php';
 	$html = DocsetRenderer::renderInlineHtml((string)file_get_contents($doc['file']), $repo, 'PHP', dirname($doc['relative']));
 	assert_true(str_contains($html, 'array_map'), 'inline renderer includes document content');
 	$rewrittenLink = str_replace('&', '&amp;', URL::Link('view', array('docset' => 'PHP', 'path' => 'www.php.net/manual/en/language.types.array.html')));