diff --git a/packages/core/src/sanitization/inert_body.ts b/packages/core/src/sanitization/inert_body.ts
index 62c6598df8..0d7173f01a 100644
--- a/packages/core/src/sanitization/inert_body.ts
+++ b/packages/core/src/sanitization/inert_body.ts
@@ -32,8 +32,9 @@ class DOMParserHelper implements InertBodyHelper {
   getInertBodyElement(html: string): HTMLElement|null {
     // We add these extra elements to ensure that the rest of the content is parsed as expected
     // e.g. leading whitespace is maintained and tags like `<meta>` do not get hoisted to the
-    // `<head>` tag.
-    html = '<body><remove></remove>' + html + '</body>';
+    // `<head>` tag. Note that the `<body>` tag is closed implicitly to prevent unclosed tags
+    // in `html` from consuming the otherwise explicit `</body>` tag.
+    html = '<body><remove></remove>' + html;
     try {
       const body = new (window as any).DOMParser().parseFromString(html, 'text/html').body as
           HTMLBodyElement;
diff --git a/packages/core/test/sanitization/html_sanitizer_spec.ts b/packages/core/test/sanitization/html_sanitizer_spec.ts
index dc83ca31f5..d577ce2c4d 100644
--- a/packages/core/test/sanitization/html_sanitizer_spec.ts
+++ b/packages/core/test/sanitization/html_sanitizer_spec.ts
@@ -173,6 +173,27 @@ import {isDOMParserAvailable} from '../../src/sanitization/inert_body';
       expect(logMsgs.join('\n')).toMatch(/sanitizing HTML stripped some content/);
     });
 
+    it('should strip unclosed iframe tag', () => {
+      expect(_sanitizeHtml(defaultDoc, '<iframe>')).toEqual('');
+      expect([
+        '&lt;iframe&gt;',
+        // Double-escaped on IE
+        '&amp;lt;iframe&amp;gt;'
+      ]).toContain(_sanitizeHtml(defaultDoc, '<iframe><iframe>'));
+      expect([
+        '&lt;script&gt;evil();&lt;/script&gt;',
+        // Double-escaped on IE
+        '&amp;lt;script&amp;gt;evil();&amp;lt;/script&amp;gt;'
+      ]).toContain(_sanitizeHtml(defaultDoc, '<iframe><script>evil();</script>'));
+    });
+
+    it('should ignore extraneous body tags', () => {
+      expect(_sanitizeHtml(defaultDoc, '</body>')).toEqual('');
+      expect(_sanitizeHtml(defaultDoc, 'foo</body>bar')).toEqual('foobar');
+      expect(_sanitizeHtml(defaultDoc, 'foo<body>bar')).toEqual('foobar');
+      expect(_sanitizeHtml(defaultDoc, 'fo<body>ob</body>ar')).toEqual('foobar');
+    });
+
     it('should not enter an infinite loop on clobbered elements', () => {
       // Some browsers are vulnerable to clobbered elements and will throw an expected exception
       // IE and EDGE does not seems to be affected by those cases
