diff --git a/core/src/main/java/hudson/Functions.java b/core/src/main/java/hudson/Functions.java
index a330a042bf..632961ecab 100644
--- a/core/src/main/java/hudson/Functions.java
+++ b/core/src/main/java/hudson/Functions.java
@@ -123,6 +123,8 @@ import java.util.logging.Logger;
 import java.util.logging.SimpleFormatter;
 import java.util.regex.Pattern;
 import org.apache.commons.lang.StringUtils;
+import org.kohsuke.accmod.Restricted;
+import org.kohsuke.accmod.restrictions.NoExternalUse;
 
 /**
  * Utility functions used in views.
@@ -426,6 +428,15 @@ public class Functions {
         return c.getValue();
     }
 
+    private static final Pattern ICON_SIZE = Pattern.compile("\\d+x\\d+");
+    @Restricted(NoExternalUse.class)
+    public static String validateIconSize(String iconSize) throws SecurityException {
+        if (!ICON_SIZE.matcher(iconSize).matches()) {
+            throw new SecurityException("invalid iconSize");
+        }
+        return iconSize;
+    }
+
     /**
      * Gets the suffix to use for YUI JavaScript.
      */
diff --git a/core/src/main/java/hudson/model/View.java b/core/src/main/java/hudson/model/View.java
index 7bcc7ce5cb..cae3307659 100644
--- a/core/src/main/java/hudson/model/View.java
+++ b/core/src/main/java/hudson/model/View.java
@@ -766,7 +766,7 @@ public abstract class View extends AbstractModelObject implements AccessControll
 
         {
             StaplerRequest req = Stapler.getCurrentRequest();
-            iconSize = req != null ? Functions.getCookie(req, "iconSize", "32x32") : "32x32";
+            iconSize = req != null ? Functions.validateIconSize(Functions.getCookie(req, "iconSize", "32x32")) : "32x32";
         }
 
         @Override protected void compute() throws Exception {
diff --git a/core/src/main/java/jenkins/model/Jenkins.java b/core/src/main/java/jenkins/model/Jenkins.java
index 8d0802736d..ee0098ebe4 100755
--- a/core/src/main/java/jenkins/model/Jenkins.java
+++ b/core/src/main/java/jenkins/model/Jenkins.java
@@ -295,7 +295,6 @@ import java.util.logging.Level;
 import static java.util.logging.Level.SEVERE;
 import java.util.logging.LogRecord;
 import java.util.logging.Logger;
-import java.util.regex.Pattern;
 import javax.annotation.CheckForNull;
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
@@ -3417,9 +3416,9 @@ public class Jenkins extends AbstractCIBase implements ModifiableTopLevelItemGro
      */
     public void doIconSize( StaplerRequest req, StaplerResponse rsp ) throws IOException, ServletException {
         String qs = req.getQueryString();
-        if(qs==null || !ICON_SIZE.matcher(qs).matches())
+        if(qs==null)
             throw new ServletException();
-        Cookie cookie = new Cookie("iconSize", qs);
+        Cookie cookie = new Cookie("iconSize", Functions.validateIconSize(qs));
         cookie.setMaxAge(/* ~4 mo. */9999999); // #762
         rsp.addCookie(cookie);
         String ref = req.getHeader("Referer");
@@ -3964,8 +3963,6 @@ public class Jenkins extends AbstractCIBase implements ModifiableTopLevelItemGro
 
     private static final Logger LOGGER = Logger.getLogger(Jenkins.class.getName());
 
-    private static final Pattern ICON_SIZE = Pattern.compile("\\d+x\\d+");
-
     public static final PermissionGroup PERMISSIONS = Permission.HUDSON_PERMISSIONS;
     public static final Permission ADMINISTER = Permission.HUDSON_ADMINISTER;
     public static final Permission READ = new Permission(PERMISSIONS,"Read",Messages._Hudson_ReadPermission_Description(),Permission.READ,PermissionScope.JENKINS);
diff --git a/core/src/main/resources/lib/hudson/setIconSize.jelly b/core/src/main/resources/lib/hudson/setIconSize.jelly
index 138c220ae0..bf9e7a0c05 100644
--- a/core/src/main/resources/lib/hudson/setIconSize.jelly
+++ b/core/src/main/resources/lib/hudson/setIconSize.jelly
@@ -27,7 +27,7 @@ THE SOFTWARE.
 -->
 <?jelly escape-by-default='true'?>
 <j:jelly xmlns:j="jelly:core" xmlns:x="jelly:xml" xmlns:st="jelly:stapler" xmlns:d="jelly:define" xmlns:l="/lib/layout" xmlns:t="/lib/hudson" xmlns:f="/lib/form">
-  <j:set scope="parent" var="iconSize" value="${h.getCookie(request,'iconSize','32x32')}" />
+  <j:set scope="parent" var="iconSize" value="${h.validateIconSize(h.getCookie(request,'iconSize','32x32'))}" />
   <!--
     balls look smaller than their actual size,
     so we try not to make the secondary icons look bigger than the icon.