diff --git a/spring-core/src/main/java/org/springframework/util/xml/XmlValidationModeDetector.java b/spring-core/src/main/java/org/springframework/util/xml/XmlValidationModeDetector.java
index 3c78313bd0d..31671eabe73 100644
--- a/spring-core/src/main/java/org/springframework/util/xml/XmlValidationModeDetector.java
+++ b/spring-core/src/main/java/org/springframework/util/xml/XmlValidationModeDetector.java
@@ -151,7 +151,9 @@ public class XmlValidationModeDetector {
 	private String consumeCommentTokens(String line) {
 		int indexOfStartComment = line.indexOf(START_COMMENT);
 		if (indexOfStartComment == -1 && !line.contains(END_COMMENT)) {
-			return line;
+			// If we are inside a multi-line comment, the entire line is comment
+			// data and must not be treated as content.
+			return (this.inComment ? "" : line);
 		}
 
 		String result = "";
diff --git a/spring-core/src/test/java/org/springframework/util/xml/XmlValidationModeDetectorTests.java b/spring-core/src/test/java/org/springframework/util/xml/XmlValidationModeDetectorTests.java
index 9714eef1c64..15a97691c1e 100644
--- a/spring-core/src/test/java/org/springframework/util/xml/XmlValidationModeDetectorTests.java
+++ b/spring-core/src/test/java/org/springframework/util/xml/XmlValidationModeDetectorTests.java
@@ -44,7 +44,8 @@ class XmlValidationModeDetectorTests {
 		"dtdWithTrailingComment.xml",
 		"dtdWithTrailingCommentAcrossMultipleLines.xml",
 		"dtdWithCommentOnNextLine.xml",
-		"dtdWithMultipleComments.xml"
+		"dtdWithMultipleComments.xml",
+		"dtdWithDoctypeInMultiLineCommentBody.xml"
 	})
 	void dtdDetection(String fileName) throws Exception {
 		assertValidationMode(fileName, VALIDATION_DTD);
@@ -55,7 +56,9 @@ class XmlValidationModeDetectorTests {
 		"xsdWithNoComments.xml",
 		"xsdWithMultipleComments.xml",
 		"xsdWithDoctypeInComment.xml",
-		"xsdWithDoctypeInOpenCommentWithAdditionalCommentOnSameLine.xml"
+		"xsdWithDoctypeInOpenCommentWithAdditionalCommentOnSameLine.xml",
+		"xsdWithDoctypeInMultiLineCommentBody.xml",
+		"xsdWithMultipleDoctypesInMultiLineCommentBody.xml"
 	})
 	void xsdDetection(String fileName) throws Exception {
 		assertValidationMode(fileName, VALIDATION_XSD);
diff --git a/spring-core/src/test/resources/org/springframework/util/xml/dtdWithDoctypeInMultiLineCommentBody.xml b/spring-core/src/test/resources/org/springframework/util/xml/dtdWithDoctypeInMultiLineCommentBody.xml
new file mode 100644
index 00000000000..9256a3103b0
--- /dev/null
+++ b/spring-core/src/test/resources/org/springframework/util/xml/dtdWithDoctypeInMultiLineCommentBody.xml
@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+	DOCTYPE
+-->
+<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN 2.0//EN" "https://www.springframework.org/dtd/spring-beans-2.0.dtd">
+<beans>
+
+</beans>
diff --git a/spring-core/src/test/resources/org/springframework/util/xml/xsdWithDoctypeInMultiLineCommentBody.xml b/spring-core/src/test/resources/org/springframework/util/xml/xsdWithDoctypeInMultiLineCommentBody.xml
new file mode 100644
index 00000000000..2a34756ee05
--- /dev/null
+++ b/spring-core/src/test/resources/org/springframework/util/xml/xsdWithDoctypeInMultiLineCommentBody.xml
@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+	See the DOCTYPE notes for legacy configs
+-->
+<beans xmlns="http://www.springframework.org/schema/beans"
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="https://www.springframework.org/schema/beans
+		https://www.springframework.org/schema/beans/spring-beans.xsd">
+
+</beans>
diff --git a/spring-core/src/test/resources/org/springframework/util/xml/xsdWithMultipleDoctypesInMultiLineCommentBody.xml b/spring-core/src/test/resources/org/springframework/util/xml/xsdWithMultipleDoctypesInMultiLineCommentBody.xml
new file mode 100644
index 00000000000..87a39cdaaf8
--- /dev/null
+++ b/spring-core/src/test/resources/org/springframework/util/xml/xsdWithMultipleDoctypesInMultiLineCommentBody.xml
@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+	xxx DOCTYPE xxx
+	yyy
+	zzz DOCTYPE zzz
+-->
+<beans xmlns="http://www.springframework.org/schema/beans"
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="https://www.springframework.org/schema/beans
+		https://www.springframework.org/schema/beans/spring-beans.xsd">
+
+</beans>