diff --git a/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/pulsar/PulsarPropertiesMapper.java b/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/pulsar/PulsarPropertiesMapper.java
index 9c33ad4d099a..cad895b269dd 100644
--- a/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/pulsar/PulsarPropertiesMapper.java
+++ b/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/pulsar/PulsarPropertiesMapper.java
@@ -137,7 +137,7 @@ private String getAuthenticationParamsJson(Map<String, String> params) {
 		try {
 			return sortedParams.entrySet()
 				.stream()
-				.map((entry) -> "\"%s\":\"%s\"".formatted(entry.getKey(), entry.getValue()))
+				.map((entry) -> "\"%s\":\"%s\"".formatted(entry.getKey(), escapeJson(entry.getValue())))
 				.collect(Collectors.joining(",", "{", "}"));
 		}
 		catch (Exception ex) {
@@ -145,6 +145,17 @@ private String getAuthenticationParamsJson(Map<String, String> params) {
 		}
 	}
 
+	private String escapeJson(String raw) {
+		return raw.replace("\\", "\\\\")
+			.replace("\"", "\\\"")
+			.replace("/", "\\/")
+			.replace("\b", "\\b")
+			.replace("\t", "\\t")
+			.replace("\n", "\\n")
+			.replace("\f", "\\f")
+			.replace("\r", "\\r");
+	}
+
 	<T> void customizeProducerBuilder(ProducerBuilder<T> producerBuilder) {
 		PulsarProperties.Producer properties = this.properties.getProducer();
 		PropertyMapper map = PropertyMapper.get().alwaysApplyingWhenNonNull();
diff --git a/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/pulsar/PulsarPropertiesMapperTests.java b/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/pulsar/PulsarPropertiesMapperTests.java
index ea055faa002d..f23584aab0ab 100644
--- a/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/pulsar/PulsarPropertiesMapperTests.java
+++ b/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/pulsar/PulsarPropertiesMapperTests.java
@@ -81,8 +81,10 @@ void customizeClientBuilderWhenHasNoAuthentication() {
 	@Test
 	void customizeClientBuilderWhenHasAuthentication() throws UnsupportedAuthenticationException {
 		PulsarProperties properties = new PulsarProperties();
-		Map<String, String> params = Map.of("param", "name");
-		String authParamString = "{\"param\":\"name\"}";
+		Map<String, String> params = Map.of("simpleParam", "foo", "complexParam",
+				"{\n\t\"k1\" : \"v1\",\n\t\"k2\":\"v2\"\n}");
+		String authParamString = "{\"complexParam\":\"{\\n\\t\\\"k1\\\" : \\\"v1\\\",\\n\\t\\\"k2\\\":\\\"v2\\\"\\n}\""
+				+ ",\"simpleParam\":\"foo\"}";
 		properties.getClient().getAuthentication().setPluginClassName("myclass");
 		properties.getClient().getAuthentication().setParam(params);
 		ClientBuilder builder = mock(ClientBuilder.class);
@@ -166,8 +168,10 @@ void customizeAdminBuilderWhenHasNoAuthentication() {
 	@Test
 	void customizeAdminBuilderWhenHasAuthentication() throws UnsupportedAuthenticationException {
 		PulsarProperties properties = new PulsarProperties();
-		Map<String, String> params = Map.of("param", "name");
-		String authParamString = "{\"param\":\"name\"}";
+		Map<String, String> params = Map.of("simpleParam", "foo", "complexParam",
+				"{\n\t\"k1\" : \"v1\",\n\t\"k2\":\"v2\"\n}");
+		String authParamString = "{\"complexParam\":\"{\\n\\t\\\"k1\\\" : \\\"v1\\\",\\n\\t\\\"k2\\\":\\\"v2\\\"\\n}\""
+				+ ",\"simpleParam\":\"foo\"}";
 		properties.getAdmin().getAuthentication().setPluginClassName("myclass");
 		properties.getAdmin().getAuthentication().setParam(params);
 		PulsarAdminBuilder builder = mock(PulsarAdminBuilder.class);