diff --git a/jspwiki-main/src/main/java/org/apache/wiki/plugin/IfPlugin.java b/jspwiki-main/src/main/java/org/apache/wiki/plugin/IfPlugin.java
index 5c33257449..d4a749a50e 100644
--- a/jspwiki-main/src/main/java/org/apache/wiki/plugin/IfPlugin.java
+++ b/jspwiki-main/src/main/java/org/apache/wiki/plugin/IfPlugin.java
@@ -27,10 +27,12 @@ Licensed to the Apache Software Foundation (ASF) under one
 import org.apache.oro.text.regex.Perl5Compiler;
 import org.apache.oro.text.regex.Perl5Matcher;
 import org.apache.wiki.api.core.Context;
+import org.apache.wiki.api.core.Page;
 import org.apache.wiki.api.exceptions.PluginException;
 import org.apache.wiki.api.plugin.Plugin;
 import org.apache.wiki.api.providers.WikiProvider;
 import org.apache.wiki.auth.AuthorizationManager;
+import org.apache.wiki.auth.permissions.PermissionFactory;
 import org.apache.wiki.pages.PageManager;
 import org.apache.wiki.render.RenderingManager;
 import org.apache.wiki.util.HttpUtil;
@@ -190,7 +192,15 @@ public static boolean ifInclude( final Context context, final Map< String, Strin
         include |= checkIP(context, ip);
 
         if( page != null ) {
-            final String content = context.getEngine().getManager( PageManager.class ).getPureText(page, WikiProvider.LATEST_VERSION).trim();
+            // Only read the target page's content if the requesting session is allowed to view it;
+            // otherwise behave exactly as if the content did not match, so ACL-protected content
+            // cannot be probed through the contains/is parameters.
+            String content = null;
+            final Page testedPage = context.getEngine().getManager( PageManager.class ).getPage( page );
+            if( testedPage != null && context.getEngine().getManager( AuthorizationManager.class )
+                    .checkPermission( context.getWikiSession(), PermissionFactory.getPagePermission( testedPage, "view" ) ) ) {
+                content = context.getEngine().getManager( PageManager.class ).getPureText(page, WikiProvider.LATEST_VERSION).trim();
+            }
             include |= checkContains(content,contains);
             include |= checkIs(content,is);
             include |= checkExists(context,page,exists);
diff --git a/jspwiki-main/src/test/java/org/apache/wiki/plugin/IfPluginTest.java b/jspwiki-main/src/test/java/org/apache/wiki/plugin/IfPluginTest.java
index 0f06c5a43b..8002e5ce95 100644
--- a/jspwiki-main/src/test/java/org/apache/wiki/plugin/IfPluginTest.java
+++ b/jspwiki-main/src/test/java/org/apache/wiki/plugin/IfPluginTest.java
@@ -44,6 +44,7 @@ class IfPluginTest {
     @AfterEach
     public void tearDown() throws Exception {
         testEngine.getManager( PageManager.class ).deletePage( "Test" );
+        testEngine.getManager( PageManager.class ).deletePage( "SecretPage" );
     }
 
     /**
@@ -168,4 +169,25 @@ void testIfPluginIPNotAllowed() throws WikiException {
         Assertions.assertEquals( expected, res );
     }
 
+    /**
+     * Checks that an ACL-protected page cannot be probed through the contains parameter:
+     * a denied page must behave exactly as if its content did not match.
+     *
+     * @throws WikiException test Assertions.failing.
+     */
+    @Test
+    void testIfPluginContainsAclProtectedPageNotLeaked() throws WikiException {
+        testEngine.saveText( "SecretPage", "[{ALLOW view Alice}]\nxyzzy" );
+
+        final String src = "[{IfPlugin page='SecretPage' contains='xyzzy'\n\nSecret page contains xyzzy}]";
+        final String expected = "\n";
+
+        testEngine.saveText( "Test", src );
+        final Page page = testEngine.getManager( PageManager.class ).getPage( "Test", PageProvider.LATEST_VERSION );
+        final Context context = getJanneBasedWikiContextFor( page );
+
+        final String res = testEngine.getManager( RenderingManager.class ).getHTML( context, page );
+        Assertions.assertEquals( expected, res );
+    }
+
 }