diff --git a/src/java.base/share/classes/java/net/InetAddress.java b/src/java.base/share/classes/java/net/InetAddress.java
index faa0d085244..e57e2741244 100644
--- a/src/java.base/share/classes/java/net/InetAddress.java
+++ b/src/java.base/share/classes/java/net/InetAddress.java
@@ -1508,6 +1508,10 @@ public sealed class InetAddress implements Serializable permits Inet4Address, In
             InetAddress[] ret = new InetAddress[1];
             if(addr != null) {
                 if (addr.length == Inet4Address.INADDRSZ) {
+                    if (numericZone != -1 || ifname != null) {
+                        // IPv4-mapped address must not contain zone-id
+                        throw new UnknownHostException(host + ": invalid IPv4-mapped address");
+                    }
                     ret[0] = new Inet4Address(null, addr);
                 } else {
                     if (ifname != null) {
@@ -1552,22 +1556,23 @@ public sealed class InetAddress implements Serializable permits Inet4Address, In
         int percent = s.indexOf ('%');
         int slen = s.length();
         int digit, zone=0;
+        int multmax = Integer.MAX_VALUE / 10; // for int overflow detection
         if (percent == -1) {
             return -1;
         }
         for (int i=percent+1; i<slen; i++) {
             char c = s.charAt(i);
-            if (c == ']') {
-                if (i == percent+1) {
-                    /* empty per-cent field */
-                    return -1;
-                }
-                break;
+            if ((digit = IPAddressUtil.parseAsciiDigit(c, 10)) < 0) {
+                return -1;
             }
-            if ((digit = Character.digit (c, 10)) < 0) {
+            if (zone > multmax) {
                 return -1;
             }
             zone = (zone * 10) + digit;
+            if (zone < 0) {
+                return -1;
+            }
+
         }
         return zone;
     }
diff --git a/src/java.base/share/classes/sun/net/util/IPAddressUtil.java b/src/java.base/share/classes/sun/net/util/IPAddressUtil.java
index 0624a792907..28a819cc938 100644
--- a/src/java.base/share/classes/sun/net/util/IPAddressUtil.java
+++ b/src/java.base/share/classes/sun/net/util/IPAddressUtil.java
@@ -829,7 +829,7 @@ public class IPAddressUtil {
     }
 
     // Parse ASCII digit in given radix
-    private static int parseAsciiDigit(char c, int radix) {
+    public static int parseAsciiDigit(char c, int radix) {
         assert radix == OCTAL || radix == DECIMAL || radix == HEXADECIMAL;
         if (radix == HEXADECIMAL) {
             return parseAsciiHexDigit(c);