From 9bec52b1ec741976658e916850b31f41afd2da2d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=A9bastien=20Deleuze?=
 <sdeleuze@users.noreply.github.com>
Date: Fri, 1 May 2026 18:56:16 +0200
Subject: [PATCH] Add trusted packages to MappingJackson2MessageConverter

This commit introduces trusted packages, specified via the related
setter for untrusted use cases. It allows explicit configuration
of which Java packages are allowed to be deserialized.

Closes gh-36791
---
 .../MappingJackson2MessageConverter.java      | 37 +++++++++
 .../MappingJackson2MessageConverterTests.java | 82 +++++++++++++++++++
 2 files changed, 119 insertions(+)

diff --git a/spring-jms/src/main/java/org/springframework/jms/support/converter/MappingJackson2MessageConverter.java b/spring-jms/src/main/java/org/springframework/jms/support/converter/MappingJackson2MessageConverter.java
index c74ef2a81ab..e842f023496 100644
--- a/spring-jms/src/main/java/org/springframework/jms/support/converter/MappingJackson2MessageConverter.java
+++ b/spring-jms/src/main/java/org/springframework/jms/support/converter/MappingJackson2MessageConverter.java
@@ -21,6 +21,7 @@ import java.io.IOException;
 import java.io.OutputStreamWriter;
 import java.io.StringWriter;
 import java.io.UnsupportedEncodingException;
+import java.util.Arrays;
 import java.util.HashMap;
 import java.util.Map;
 
@@ -49,6 +50,8 @@ import org.springframework.util.ClassUtils;
  * {@link #setTargetType targetType} is set to {@link MessageType#TEXT}.
  * Converts from a {@link TextMessage} or {@link BytesMessage} to an object.
  *
+ * <p>For untrusted environments, use {@link #setTrustedPackages(String...)}.
+ *
  * <p>It customizes Jackson's default properties with the following ones:
  * <ul>
  * <li>{@link MapperFeature#DEFAULT_VIEW_INCLUSION} is disabled</li>
@@ -59,6 +62,7 @@ import org.springframework.util.ClassUtils;
  * @author Dave Syer
  * @author Juergen Hoeller
  * @author Stephane Nicoll
+ * @author Sebastien Deleuze
  * @since 3.1.4
  * @deprecated since 7.0 in favor of {@link JacksonJsonMessageConverter}
  */
@@ -85,11 +89,14 @@ public class MappingJackson2MessageConverter implements SmartMessageConverter, B
 
 	private final Map<Class<?>, String> classIdMappings = new HashMap<>();
 
+	private String @Nullable [] trustedPackages;
+
 	private @Nullable ClassLoader beanClassLoader;
 
 
 	/**
 	 * Construct a {@code MappingJackson2MessageConverter} with a default {@link ObjectMapper}.
+	 * @see #setTrustedPackages(String...)
 	 */
 	@SuppressWarnings("deprecation")  // on Jackson 2.13: configure(MapperFeature, boolean)
 	public MappingJackson2MessageConverter() {
@@ -102,12 +109,21 @@ public class MappingJackson2MessageConverter implements SmartMessageConverter, B
 	 * Construct a {@code MappingJackson2MessageConverter} with a custom {@link ObjectMapper}.
 	 * @param objectMapper the {@code ObjectMapper} to use
 	 * @since 6.1
+	 * @see #setTrustedPackages(String...)
 	 */
 	public MappingJackson2MessageConverter(ObjectMapper objectMapper) {
 		Assert.notNull(objectMapper, "ObjectMapper must not be null");
 		this.objectMapper = objectMapper;
 	}
 
+	/**
+	 * Specify the trusted Java packages for deserialization.
+	 * @param trustedPackages the trusted Java packages for deserialization
+	 * @since 6.2.19
+	 */
+	public void setTrustedPackages(String... trustedPackages) {
+		this.trustedPackages = trustedPackages.clone();
+	}
 
 	/**
 	 * Set the {@code ObjectMapper} for this converter.
@@ -181,6 +197,23 @@ public class MappingJackson2MessageConverter implements SmartMessageConverter, B
 		});
 	}
 
+	private boolean isTrustedPackage(String requestedType) {
+		if (this.trustedPackages != null) {
+			String packageName = ClassUtils.getPackageName(requestedType);
+			int lastBracketIndex = packageName.lastIndexOf('[');
+			if (lastBracketIndex != -1 && packageName.length() > lastBracketIndex + 1 && packageName.charAt(lastBracketIndex + 1) == 'L') {
+				packageName = packageName.substring(lastBracketIndex + 2);
+			}
+			for (String trustedPackage : this.trustedPackages) {
+				if (packageName.equals(trustedPackage)) {
+					return true;
+				}
+			}
+			return false;
+		}
+		return true;
+	}
+
 	@Override
 	public void setBeanClassLoader(ClassLoader classLoader) {
 		this.beanClassLoader = classLoader;
@@ -461,6 +494,10 @@ public class MappingJackson2MessageConverter implements SmartMessageConverter, B
 		if (mappedClass != null) {
 			return this.objectMapper.constructType(mappedClass);
 		}
+		if (!isTrustedPackage(typeId)) {
+			throw new MessageConversionException("The class '" + typeId + "' is not in the trusted packages: " +
+					Arrays.toString(this.trustedPackages));
+		}
 		try {
 			Class<?> typeClass = ClassUtils.forName(typeId, this.beanClassLoader);
 			return this.objectMapper.constructType(typeClass);
diff --git a/spring-jms/src/test/java/org/springframework/jms/support/converter/MappingJackson2MessageConverterTests.java b/spring-jms/src/test/java/org/springframework/jms/support/converter/MappingJackson2MessageConverterTests.java
index f93f292f1aa..52bd6274538 100644
--- a/spring-jms/src/test/java/org/springframework/jms/support/converter/MappingJackson2MessageConverterTests.java
+++ b/spring-jms/src/test/java/org/springframework/jms/support/converter/MappingJackson2MessageConverterTests.java
@@ -37,6 +37,7 @@ import org.mockito.stubbing.Answer;
 import org.springframework.core.MethodParameter;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
 import static org.assertj.core.api.Assertions.assertThatIllegalArgumentException;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.isA;
@@ -48,6 +49,7 @@ import static org.mockito.Mockito.verify;
  * @author Arjen Poutsma
  * @author Dave Syer
  * @author Stephane Nicoll
+ * @author Sebastien Deleuze
  */
 @SuppressWarnings("removal")
 class MappingJackson2MessageConverterTests {
@@ -134,6 +136,86 @@ class MappingJackson2MessageConverterTests {
 		assertThat(unmarshalled).as("Invalid result").isEqualTo(result);
 	}
 
+	@Test
+	void fromTextMessageUntrusted() throws Exception {
+		converter = new MappingJackson2MessageConverter();
+		converter.setTrustedPackages("java.lang");
+		converter.setTypeIdPropertyName("__typeid__");
+		TextMessage textMessageMock = mock();
+
+		String text = "{\"foo\":\"bar\"}";
+		given(textMessageMock.getStringProperty("__typeid__")).willReturn(MyBean.class.getName());
+		given(textMessageMock.getText()).willReturn(text);
+
+		assertThatExceptionOfType(MessageConversionException.class)
+				.isThrownBy(() -> converter.fromMessage(textMessageMock))
+				.withMessageContaining("is not in the trusted packages");
+	}
+
+	@Test
+	void fromTextMessageTrusted() throws Exception {
+		converter = new MappingJackson2MessageConverter();
+		converter.setTrustedPackages("java.lang", "org.springframework.jms.support.converter");
+		converter.setTypeIdPropertyName("__typeid__");
+		TextMessage textMessageMock = mock();
+		MyBean unmarshalled = new MyBean("bar");
+
+		String text = "{\"foo\":\"bar\"}";
+		given(textMessageMock.getStringProperty("__typeid__")).willReturn(MyBean.class.getName());
+		given(textMessageMock.getText()).willReturn(text);
+
+		MyBean result = (MyBean) converter.fromMessage(textMessageMock);
+		assertThat(unmarshalled).as("Invalid result").isEqualTo(result);
+	}
+
+	@Test
+	void fromTextMessageTrustedEmpty() throws Exception {
+		converter = new MappingJackson2MessageConverter();
+		converter.setTrustedPackages();
+		converter.setTypeIdPropertyName("__typeid__");
+		TextMessage textMessageMock = mock();
+
+		String text = "{\"foo\":\"bar\"}";
+		given(textMessageMock.getStringProperty("__typeid__")).willReturn(MyBean.class.getName());
+		given(textMessageMock.getText()).willReturn(text);
+
+		assertThatExceptionOfType(MessageConversionException.class)
+				.isThrownBy(() -> converter.fromMessage(textMessageMock))
+				.withMessageContaining("is not in the trusted packages");
+	}
+
+	@Test
+	void fromTextMessageTrusted1DArray() throws Exception {
+		converter = new MappingJackson2MessageConverter();
+		converter.setTrustedPackages("org.springframework.jms.support.converter");
+		converter.setTypeIdPropertyName("__typeid__");
+		TextMessage textMessageMock = mock();
+		MyBean[] unmarshalled = new MyBean[] { new MyBean("bar") };
+
+		String text = "[{\"foo\":\"bar\"}]";
+		given(textMessageMock.getStringProperty("__typeid__")).willReturn("[L" + MyBean.class.getName() + ";");
+		given(textMessageMock.getText()).willReturn(text);
+
+		MyBean[] result = (MyBean[]) converter.fromMessage(textMessageMock);
+		assertThat(unmarshalled).as("Invalid result").isEqualTo(result);
+	}
+
+	@Test
+	void fromTextMessageTrusted2DArray() throws Exception {
+		converter = new MappingJackson2MessageConverter();
+		converter.setTrustedPackages("org.springframework.jms.support.converter");
+		converter.setTypeIdPropertyName("__typeid__");
+		TextMessage textMessageMock = mock();
+		MyBean[][] unmarshalled = new MyBean[][] { { new MyBean("bar") } };
+
+		String text = "[[{\"foo\":\"bar\"}]]";
+		given(textMessageMock.getStringProperty("__typeid__")).willReturn("[[L" + MyBean.class.getName() + ";");
+		given(textMessageMock.getText()).willReturn(text);
+
+		MyBean[][] result = (MyBean[][]) converter.fromMessage(textMessageMock);
+		assertThat(unmarshalled).as("Invalid result").isEqualTo(result);
+	}
+
 	@Test
 	void fromTextMessageWithUnknownProperty() throws Exception {
 		TextMessage textMessageMock = mock();