diff --git a/WebContent/WEB-INF/lib/java10-shim-20240325.1.jar b/WebContent/WEB-INF/lib/java10-shim-20240325.1.jar
new file mode 100644
index 000000000..59c87d514
Binary files /dev/null and b/WebContent/WEB-INF/lib/java10-shim-20240325.1.jar differ
diff --git a/WebContent/WEB-INF/lib/java8-shim-20240325.1.jar b/WebContent/WEB-INF/lib/java8-shim-20240325.1.jar
new file mode 100644
index 000000000..d2e2bac67
Binary files /dev/null and b/WebContent/WEB-INF/lib/java8-shim-20240325.1.jar differ
diff --git a/WebContent/WEB-INF/lib/owasp-java-html-sanitizer-20240325.1.jar b/WebContent/WEB-INF/lib/owasp-java-html-sanitizer-20240325.1.jar
new file mode 100644
index 000000000..9becef68d
Binary files /dev/null and b/WebContent/WEB-INF/lib/owasp-java-html-sanitizer-20240325.1.jar differ
diff --git a/build.gradle b/build.gradle
index 352a67a2a..e4678cfe1 100644
--- a/build.gradle
+++ b/build.gradle
@@ -243,6 +243,7 @@ test {
         includeTestsMatching "org.scada_lts.web.security.XssProtectHtmlEscapeUtilsTest"
         includeTestsMatching "org.scada_lts.web.security.XssUtilsTest"
         includeTestsMatching "org.scada_lts.web.mvc.api.validation.css.CssValidatorTestsSuite"
+        includeTestsMatching "org.scada_lts.web.security.XssUtilsTestsSuite"
     }
 
     failFast = true
diff --git a/src/org/scada_lts/web/mvc/api/UserCommentAPI.java b/src/org/scada_lts/web/mvc/api/UserCommentAPI.java
index a8260fe59..281d12c19 100644
--- a/src/org/scada_lts/web/mvc/api/UserCommentAPI.java
+++ b/src/org/scada_lts/web/mvc/api/UserCommentAPI.java
@@ -7,6 +7,7 @@
 import org.scada_lts.mango.service.UserCommentService;
 import org.scada_lts.web.beans.ApplicationBeans;
 import org.scada_lts.web.mvc.api.json.JsonUserComment;
+import org.scada_lts.web.security.XssValid;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.ResponseEntity;
 import org.springframework.stereotype.Controller;
@@ -98,6 +99,8 @@ public ResponseEntity<String> deleteUserComment(HttpServletRequest request, @Pat
     }
 
     static class CreateUserComment {
+
+        @XssValid
         private String commentText;
 
         public CreateUserComment() {
diff --git a/src/org/scada_lts/web/mvc/api/css/CssStyle.java b/src/org/scada_lts/web/mvc/api/css/CssStyle.java
index 0021b3f7f..8c919ec8c 100644
--- a/src/org/scada_lts/web/mvc/api/css/CssStyle.java
+++ b/src/org/scada_lts/web/mvc/api/css/CssStyle.java
@@ -4,10 +4,11 @@
 import com.fasterxml.jackson.annotation.JsonCreator;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import org.scada_lts.web.beans.validation.css.CssValid;
+import org.scada_lts.web.security.XssValid;
 
 public class CssStyle {
 
-    @CssValid
+    @CssValid @XssValid
     private final String content;
 
     @JsonCreator(mode = JsonCreator.Mode.PROPERTIES)
diff --git a/src/org/scada_lts/web/security/OwaspXssValidator.java b/src/org/scada_lts/web/security/OwaspXssValidator.java
new file mode 100644
index 000000000..739221f3a
--- /dev/null
+++ b/src/org/scada_lts/web/security/OwaspXssValidator.java
@@ -0,0 +1,36 @@
+package org.scada_lts.web.security;
+
+import org.scada_lts.web.beans.validation.ScadaValidator;
+import org.owasp.html.HtmlPolicyBuilder;
+import org.owasp.html.PolicyFactory;
+
+public class OwaspXssValidator implements ScadaValidator<String> {
+
+    private final PolicyFactory policyFactory;
+
+    public OwaspXssValidator() {
+        this.policyFactory = createPolicyFactory();
+    }
+
+    @Override
+    public void validate(String input) throws XssValidatorException {
+        try {
+            validateXss(input);
+        } catch (Exception e) {
+            throw new XssValidatorException("XSS validation failed: " + e.getMessage(), e);
+        }
+    }
+
+    void validateXss(String input) throws XssValidatorException {
+        String sanitized = policyFactory.sanitize(input);
+        if (!sanitized.equals(input)) {
+            throw new XssValidatorException("Potential XSS attack detected");
+        }
+    }
+
+    private PolicyFactory createPolicyFactory() {
+        return new HtmlPolicyBuilder()
+                .allowElements("b", "i", "u", "strong", "em", "p", "ul", "ol", "li")
+                .toFactory();
+    }
+}
diff --git a/src/org/scada_lts/web/security/XssConstraintValidator.java b/src/org/scada_lts/web/security/XssConstraintValidator.java
new file mode 100644
index 000000000..0915f217f
--- /dev/null
+++ b/src/org/scada_lts/web/security/XssConstraintValidator.java
@@ -0,0 +1,21 @@
+package org.scada_lts.web.security;
+
+import org.scada_lts.serorepl.utils.StringUtils;
+import org.scada_lts.web.beans.validation.AbstractConstraintValidator;
+import org.scada_lts.web.beans.validation.ScadaValidator;
+
+public class XssConstraintValidator extends AbstractConstraintValidator<XssValid, String> {
+
+    @Override
+    public void beforeValidate(String value) throws Exception {
+        if (StringUtils.isEmpty(value)) {
+            throw new XssValidatorException("Input is empty");
+        }
+    }
+
+    @Override
+    public void validate(String value) throws Exception {
+        ScadaValidator<String> validator = new OwaspXssValidator();
+        validator.validate(value);
+    }
+}
diff --git a/src/org/scada_lts/web/security/XssValid.java b/src/org/scada_lts/web/security/XssValid.java
new file mode 100644
index 000000000..6923019fd
--- /dev/null
+++ b/src/org/scada_lts/web/security/XssValid.java
@@ -0,0 +1,19 @@
+package org.scada_lts.web.security;
+
+import javax.validation.Constraint;
+import javax.validation.Payload;
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Constraint(validatedBy = XssConstraintValidator.class)
+@Target({ ElementType.FIELD, ElementType.PARAMETER })
+@Retention(RetentionPolicy.RUNTIME)
+public @interface XssValid {
+    String message() default "Potential XSS detected in the request body.";
+
+    Class<?>[] groups() default {};
+
+    Class<? extends Payload>[] payload() default {};
+}
diff --git a/src/org/scada_lts/web/security/XssValidatorException.java b/src/org/scada_lts/web/security/XssValidatorException.java
new file mode 100644
index 000000000..7208ab42e
--- /dev/null
+++ b/src/org/scada_lts/web/security/XssValidatorException.java
@@ -0,0 +1,25 @@
+package org.scada_lts.web.security;
+
+import org.scada_lts.web.beans.validation.ScadaValidatorException;
+
+public class XssValidatorException extends ScadaValidatorException {
+
+    public XssValidatorException() {
+    }
+
+    public XssValidatorException(String message) {
+        super(message);
+    }
+
+    public XssValidatorException(String message, Throwable cause) {
+        super(message, cause);
+    }
+
+    public XssValidatorException(Throwable cause) {
+        super(cause);
+    }
+
+    public XssValidatorException(String message, Throwable cause, boolean enableSuppression, boolean writableStackTrace) {
+        super(message, cause, enableSuppression, writableStackTrace);
+    }
+}
diff --git a/test/org/scada_lts/web/security/XssUtilsTestsSuite.java b/test/org/scada_lts/web/security/XssUtilsTestsSuite.java
new file mode 100644
index 000000000..ed6fb9572
--- /dev/null
+++ b/test/org/scada_lts/web/security/XssUtilsTestsSuite.java
@@ -0,0 +1,13 @@
+package org.scada_lts.web.security;
+
+import org.junit.runner.RunWith;
+import org.junit.runners.Suite;
+
+@RunWith(Suite.class)
+@Suite.SuiteClasses({
+        XssUtilsValidateHttpQueryTest.class,
+        XssUtilsValidateHttpBodyTest.class,
+        XssUtilsValidateHttpBodyExceptionTest.class
+})
+public class XssUtilsTestsSuite {
+}
\ No newline at end of file
diff --git a/test/org/scada_lts/web/security/XssUtilsValidateHttpBodyExceptionTest.java b/test/org/scada_lts/web/security/XssUtilsValidateHttpBodyExceptionTest.java
new file mode 100644
index 000000000..97d12fab3
--- /dev/null
+++ b/test/org/scada_lts/web/security/XssUtilsValidateHttpBodyExceptionTest.java
@@ -0,0 +1,40 @@
+package org.scada_lts.web.security;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+import java.util.Arrays;
+import java.util.Collection;
+
+@RunWith(Parameterized.class)
+public class XssUtilsValidateHttpBodyExceptionTest {
+
+    @Parameterized.Parameters
+    public static Collection<Object[]> testData() {
+        return Arrays.asList(new Object[][]{
+                {null},
+                {"<script>alert(1)</script>"},
+                {"<a href=\"javascript:alert(1)\">Link</a>"},
+                {"<div onclick=\"alert(1)\">Click me</div>"},
+                {"body { background-image: url('\"><img src=x onerror=alert(document.location)>'); }"},
+                {"div { content: \"<script>alert('XSS')</script>\"; }"},
+                {"h1 { font-family: \"<img src=x onerror=alert('XSS')>\"; }"},
+                {"@import url(\"javascript:alert('XSS')\");"},
+                {"div { /* comment: <img src=x onerror=alert('XSS')> */ }"},
+                {"span { content: '\"><script>alert(1)</script>'; }"},
+                {"h2 { color: expression(alert('XSS')); }"}
+        });
+    }
+
+    private final String input;
+    private final OwaspXssValidator owaspXssValidator = new OwaspXssValidator();
+
+    public XssUtilsValidateHttpBodyExceptionTest(String input) {
+        this.input = input;
+    }
+
+    @Test(expected = XssValidatorException.class)
+    public void testValidateHttpBodyException() throws XssValidatorException {
+        owaspXssValidator.validate(input);
+    }
+}
diff --git a/test/org/scada_lts/web/security/XssUtilsValidateHttpBodyTest.java b/test/org/scada_lts/web/security/XssUtilsValidateHttpBodyTest.java
new file mode 100644
index 000000000..22584408e
--- /dev/null
+++ b/test/org/scada_lts/web/security/XssUtilsValidateHttpBodyTest.java
@@ -0,0 +1,43 @@
+package org.scada_lts.web.security;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+
+import java.util.Arrays;
+import java.util.Collection;
+
+@RunWith(Parameterized.class)
+public class XssUtilsValidateHttpBodyTest {
+
+    @Parameterized.Parameters
+    public static Collection<Object[]> testData() {
+        return Arrays.asList(new Object[][]{
+                {"<b>Bold</b>"},
+                {"Hello, World!"},
+                {""},
+                {"<i>Italic text</i>"},
+                {"<u>Underlined</u>"},
+                {"<strong>Strong text</strong>"},
+                {"<em>Emphasized text</em>"},
+                {"<p>Paragraph with <b>bold</b> and <i>italic</i></p>"},
+                {"<ul><li>Item 1</li><li>Item 2</li></ul>"},
+                {"<ol><li>First</li><li>Second</li></ol>"},
+                {"body { font-size: 14px; }"},
+                {"h1 { font-weight: bold; }"},
+                {"p { margin: 0; padding: 0; }"},
+        });
+    }
+
+    private final String input;
+    private final OwaspXssValidator owaspXssValidator = new OwaspXssValidator();
+
+    public XssUtilsValidateHttpBodyTest(String input) {
+        this.input = input;
+    }
+
+    @Test
+    public void testValidateHttpBody() throws XssValidatorException {
+        owaspXssValidator.validate(input);
+    }
+}
diff --git a/test/org/scada_lts/web/security/XssUtilsTest.java b/test/org/scada_lts/web/security/XssUtilsValidateHttpQueryTest.java
similarity index 97%
rename from test/org/scada_lts/web/security/XssUtilsTest.java
rename to test/org/scada_lts/web/security/XssUtilsValidateHttpQueryTest.java
index 00902cfbe..80baa928b 100644
--- a/test/org/scada_lts/web/security/XssUtilsTest.java
+++ b/test/org/scada_lts/web/security/XssUtilsValidateHttpQueryTest.java
@@ -11,12 +11,12 @@
 import java.util.Collection;
 
 @RunWith(Parameterized.class)
-public class XssUtilsTest {
+public class XssUtilsValidateHttpQueryTest {
 
     private final String input;
     private final boolean expectedResult;
 
-    public XssUtilsTest(String input, boolean expectedResult) {
+    public XssUtilsValidateHttpQueryTest(String input, boolean expectedResult) {
         this.input = input;
         this.expectedResult = expectedResult;
     }