diff --git a/src/java.base/share/classes/javax/crypto/spec/DESKeySpec.java b/src/java.base/share/classes/javax/crypto/spec/DESKeySpec.java
index 078cb9bbefd..a2afd88c3ba 100644
--- a/src/java.base/share/classes/javax/crypto/spec/DESKeySpec.java
+++ b/src/java.base/share/classes/javax/crypto/spec/DESKeySpec.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2026, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -123,7 +123,7 @@ public class DESKeySpec implements java.security.spec.KeySpec {
      * of the buffer are copied to protect against subsequent modification.
      *
      * @exception NullPointerException if the given key material is
-     * <code>null</code>
+     * <code>null</code>.
      * @exception InvalidKeyException if the given key material is shorter
      * than 8 bytes.
      */
@@ -146,14 +146,22 @@ public class DESKeySpec implements java.security.spec.KeySpec {
      * material starts.
      *
      * @exception NullPointerException if the given key material is
-     * <code>null</code>
+     * <code>null</code>.
      * @exception InvalidKeyException if the given key material, starting at
      * <code>offset</code> inclusive, is shorter than 8 bytes.
+     * @exception ArrayIndexOutOfBoundsException if <code>offset</code> is
+     * negative.
      */
     public DESKeySpec(byte[] key, int offset) throws InvalidKeyException {
+        if (key == null) {
+            throw new NullPointerException("null key");
+        }
         if (key.length - offset < DES_KEY_LEN) {
             throw new InvalidKeyException("Wrong key size");
         }
+        if (offset < 0) {
+            throw new ArrayIndexOutOfBoundsException("offset is negative");
+        }
         this.key = new byte[DES_KEY_LEN];
         System.arraycopy(key, offset, this.key, 0, DES_KEY_LEN);
     }
@@ -182,6 +190,8 @@ public class DESKeySpec implements java.security.spec.KeySpec {
      * @exception InvalidKeyException if the given key material is
      * <code>null</code>, or starting at <code>offset</code> inclusive, is
      * shorter than 8 bytes.
+     * @exception ArrayIndexOutOfBoundsException if <code>offset</code> is
+     * negative.
      */
     public static boolean isParityAdjusted(byte[] key, int offset)
         throws InvalidKeyException {
@@ -191,7 +201,9 @@ public class DESKeySpec implements java.security.spec.KeySpec {
             if (key.length - offset < DES_KEY_LEN) {
                 throw new InvalidKeyException("Wrong key size");
             }
-
+            if (offset < 0) {
+                throw new ArrayIndexOutOfBoundsException("offset is negative");
+            }
             for (int i = 0; i < DES_KEY_LEN; i++) {
                 int k = Integer.bitCount(key[offset++] & 0xff);
                 if ((k & 1) == 0) {
@@ -215,6 +227,8 @@ public class DESKeySpec implements java.security.spec.KeySpec {
      * @exception InvalidKeyException if the given key material is
      * <code>null</code>, or starting at <code>offset</code> inclusive, is
      * shorter than 8 bytes.
+     * @exception ArrayIndexOutOfBoundsException if <code>offset</code> is
+     * negative.
      */
     public static boolean isWeak(byte[] key, int offset)
         throws InvalidKeyException {
@@ -224,6 +238,9 @@ public class DESKeySpec implements java.security.spec.KeySpec {
         if (key.length - offset < DES_KEY_LEN) {
             throw new InvalidKeyException("Wrong key size");
         }
+        if (offset < 0) {
+            throw new ArrayIndexOutOfBoundsException("offset is negative");
+        }
         for (int i = 0; i < WEAK_KEYS.length; i++) {
             boolean found = true;
             for (int j = 0; j < DES_KEY_LEN; j++) {
diff --git a/src/java.base/share/classes/javax/crypto/spec/DESedeKeySpec.java b/src/java.base/share/classes/javax/crypto/spec/DESedeKeySpec.java
index 7fd5576c487..fb5a19b4a9b 100644
--- a/src/java.base/share/classes/javax/crypto/spec/DESedeKeySpec.java
+++ b/src/java.base/share/classes/javax/crypto/spec/DESedeKeySpec.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2026, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -78,14 +78,22 @@ public class DESedeKeySpec implements java.security.spec.KeySpec {
      *
      * @exception NullPointerException if <code>key</code> is null.
      * @exception InvalidKeyException if the given key material, starting at
-     * <code>offset</code> inclusive, is shorter than 24 bytes
+     * <code>offset</code> inclusive, is shorter than 24 bytes.
+     * @exception ArrayIndexOutOfBoundsException if <code>offset</code> is
+     * negative.
      */
     public DESedeKeySpec(byte[] key, int offset) throws InvalidKeyException {
-        if (key.length - offset < 24) {
+        if (key == null) {
+            throw new NullPointerException("null key");
+        }
+        if (key.length - offset < DES_EDE_KEY_LEN) {
             throw new InvalidKeyException("Wrong key size");
         }
+        if (offset < 0) {
+            throw new ArrayIndexOutOfBoundsException("offset is negative");
+        }
         this.key = new byte[24];
-        System.arraycopy(key, offset, this.key, 0, 24);
+        System.arraycopy(key, offset, this.key, 0, DES_EDE_KEY_LEN);
     }
 
     /**
@@ -107,15 +115,23 @@ public class DESedeKeySpec implements java.security.spec.KeySpec {
      * @return true if the given DES-EDE key is parity-adjusted, false
      * otherwise
      *
-     * @exception NullPointerException if <code>key</code> is null.
-     * @exception InvalidKeyException if the given key material, starting at
-     * <code>offset</code> inclusive, is shorter than 24 bytes
+     * @exception InvalidKeyException if the given key material is
+     * <code>null</code>, or starting at <code>offset</code> inclusive, is
+     * shorter than 8 bytes.
+     * @exception ArrayIndexOutOfBoundsException if <code>offset</code> is
+     * negative.
      */
     public static boolean isParityAdjusted(byte[] key, int offset)
         throws InvalidKeyException {
-            if (key.length - offset < 24) {
-                throw new InvalidKeyException("Wrong key size");
-            }
+        if (key == null) {
+            throw new InvalidKeyException("null key");
+        }
+        if (key.length - offset < DES_EDE_KEY_LEN) {
+            throw new InvalidKeyException("Wrong key size");
+        }
+        if (offset < 0) {
+            throw new ArrayIndexOutOfBoundsException("offset is negative");
+        }
         return DESKeySpec.isParityAdjusted(key, offset)
                 && DESKeySpec.isParityAdjusted(key, offset + 8)
                 && DESKeySpec.isParityAdjusted(key, offset + 16);
diff --git a/test/jdk/javax/crypto/spec/DESKeySpec/NullKey.java b/test/jdk/javax/crypto/spec/DESKeySpec/NullKey.java
index cd44b6ee216..859d721fff5 100644
--- a/test/jdk/javax/crypto/spec/DESKeySpec/NullKey.java
+++ b/test/jdk/javax/crypto/spec/DESKeySpec/NullKey.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2004, 2007, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2004, 2026, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -23,18 +23,19 @@
 
 /*
  * @test
- * @bug 4959570
+ * @bug 4959570 8364121
  * @summary DESKeySpec constructors and static methods should throw exception
  *   if the key parameter is null.
  * @author Sean Mullan
  */
 import java.security.InvalidKeyException;
+import javax.crypto.spec.DESedeKeySpec;
 import javax.crypto.spec.DESKeySpec;
 
 public class NullKey {
 
     public static void main(String[] args) throws Exception {
-
+        // Test single-DES
         try {
             DESKeySpec desSpec = new DESKeySpec(null);
             throw new Exception("expected NullPointerException");
@@ -55,5 +56,21 @@ public class NullKey {
             throw new Exception("expected InvalidKeyException");
         } catch (InvalidKeyException ike) {}
 
+        // Test triple-DES
+        try {
+            DESedeKeySpec desSpec = new DESedeKeySpec(null);
+            throw new Exception("expected NullPointerException");
+        } catch (NullPointerException npe) {}
+
+        try {
+            DESedeKeySpec desSpec = new DESedeKeySpec(null, 0);
+            throw new Exception("expected NullPointerException");
+        } catch (NullPointerException npe) {}
+
+        try {
+            boolean parityAdjusted = DESedeKeySpec.isParityAdjusted(null, 0);
+            throw new Exception("expected InvalidKeyException");
+        } catch (InvalidKeyException ike) {}
     }
+
 }
diff --git a/test/jdk/javax/crypto/spec/DESKeySpec/OffsetKey.java b/test/jdk/javax/crypto/spec/DESKeySpec/OffsetKey.java
new file mode 100644
index 00000000000..c97bb819ba2
--- /dev/null
+++ b/test/jdk/javax/crypto/spec/DESKeySpec/OffsetKey.java
@@ -0,0 +1,72 @@
+/*
+ * Copyright (c) 2026, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @bug 8364121
+ * @summary DESKeySpec.isWeak should throw aiobe exception if the offset is
+ * negative.
+ */
+import java.security.InvalidKeyException;
+import javax.crypto.spec.DESedeKeySpec;
+import javax.crypto.spec.DESKeySpec;
+
+public class OffsetKey {
+
+    public static void main(String[] args) throws Exception {
+        byte[] strongKey = {
+                (byte)0x12, (byte)0x34, (byte)0x56, (byte)0x78,
+                (byte)0x9A, (byte)0xBC, (byte)0xDE, (byte)0xF0,
+                (byte)0x12, (byte)0x34, (byte)0x56, (byte)0x78,
+                (byte)0x9A, (byte)0xBC, (byte)0xDE, (byte)0xF0,
+                (byte)0x12, (byte)0x34, (byte)0x56, (byte)0x78,
+                (byte)0x9A, (byte)0xBC, (byte)0xDE, (byte)0xF0
+        };
+
+        // Test single-DES
+        try {
+            DESKeySpec desKey = new DESKeySpec(strongKey, -1);
+            throw new Exception("expected ArrayIndexOutOfBoundsException");
+        } catch (ArrayIndexOutOfBoundsException aiobe) {}
+        try {
+            boolean weak = DESKeySpec.isWeak(strongKey, -1);
+            throw new Exception("expected ArrayIndexOutOfBoundsException");
+        } catch (ArrayIndexOutOfBoundsException aiobe) {}
+        try{
+            boolean parityAdjusted = DESKeySpec.isParityAdjusted(strongKey, -1);
+            throw new Exception("expected ArrayIndexOutOfBoundsException");
+        } catch (ArrayIndexOutOfBoundsException aiobe) {}
+
+        // Test triple-DES
+        try{
+            DESedeKeySpec desEdeKey = new DESedeKeySpec(strongKey, -1);
+            throw new Exception("expected ArrayIndexOutOfBoundsException");
+        } catch (ArrayIndexOutOfBoundsException aiobe) {}
+        try{
+            boolean parityAdjusted = DESedeKeySpec.isParityAdjusted(strongKey,
+                    -1);
+            throw new Exception("expected ArrayIndexOutOfBoundsException");
+        } catch (ArrayIndexOutOfBoundsException aiobe) {}
+    }
+
+}