Do not validate ignoredRequests from WebSecurity.ignoring()

config/src/main/java/org/springframework/security/config/annotation/web/builders/WebSecurityFilterChainValidator.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2024 the original author or authors.
+ * Copyright 2002-2025 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -52,6 +52,9 @@ public void validate(FilterChainProxy filterChainProxy) {
 	private void checkForAnyRequestRequestMatcher(List<SecurityFilterChain> chains) {
 		DefaultSecurityFilterChain anyRequestFilterChain = null;
 		for (SecurityFilterChain chain : chains) {
+			if (isWebIgnoredRequests(chain)) {
+				continue;
+			}
 			if (anyRequestFilterChain != null) {
 				String message = "A filter chain that matches any request [" + anyRequestFilterChain
 						+ "] has already been configured, which means that this filter chain [" + chain
@@ -69,6 +72,9 @@ private void checkForAnyRequestRequestMatcher(List<SecurityFilterChain> chains)
 	private void checkForDuplicateMatchers(List<SecurityFilterChain> chains) {
 		DefaultSecurityFilterChain filterChain = null;
 		for (SecurityFilterChain chain : chains) {
+			if (isWebIgnoredRequests(chain)) {
+				continue;
+			}
 			if (filterChain != null) {
 				if (chain instanceof DefaultSecurityFilterChain defaultChain) {
 					if (defaultChain.getRequestMatcher().equals(filterChain.getRequestMatcher())) {
@@ -110,4 +116,8 @@ private void checkAuthorizationFilters(List<SecurityFilterChain> chains) {
 		}
 	}
 
+	private boolean isWebIgnoredRequests(SecurityFilterChain chain) {
+		return chain.getFilters().isEmpty();
+	}
+
 }

config/src/test/java/org/springframework/security/config/annotation/web/configurers/DefaultFiltersTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2022 the original author or authors.
+ * Copyright 2002-2025 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -142,6 +142,32 @@ public void defaultFiltersPermitAll() throws IOException, ServletException {
 		assertThat(response.getRedirectedUrl()).isEqualTo("/login?logout");
 	}
 
+	@Test
+	public void validateWhenUseIgnoredRequests() {
+		this.spring.register(FilterChainProxyWithWebSecurityCustomizer.class);
+		List<SecurityFilterChain> filterChains = this.spring.getContext()
+			.getBean(FilterChainProxy.class)
+			.getFilterChains();
+		assertThat(filterChains.size()).isEqualTo(2);
+	}
+
+	@Configuration
+	@EnableWebSecurity
+	@EnableWebMvc
+	static class FilterChainProxyWithWebSecurityCustomizer {
+
+		@Bean
+		WebSecurityCustomizer webSecurityCustomizer() {
+			return (web) -> web.ignoring().anyRequest();
+		}
+
+		@Bean
+		SecurityFilterChain filterChain(HttpSecurity http) throws Exception {
+			return http.authorizeHttpRequests((a) -> a.anyRequest().authenticated()).build();
+		}
+
+	}
+
 	@Configuration
 	@EnableWebSecurity
 	static class FilterChainProxyBuilderMissingConfig {