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fix(security): replace permissive CORS wildcard with explicit allowlist #121

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Merged
epugh merged 2 commits into from
May 8, 2026
+20 −3
Merged

fix(security): replace permissive CORS wildcard with explicit allowlist #121

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8fe50a7
fix(security): replace permissive CORS wildcard with explicit allowlist
adityamparikh May 2, 2026
6fda787
Merge branch 'main' into fix/security-cors-allowlist
epugh May 8, 2026
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19 changes: 16 additions & 3 deletions src/main/java/org/apache/solr/mcp/server/security/HttpSecurityConfiguration.java
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Original file line number Diff line number Diff line change
Expand Up @@ -39,6 +39,9 @@ class HttpSecurityConfiguration {
@Value("${spring.security.oauth2.resourceserver.jwt.issuer-uri:}")
private String issuerUrl;

@Value("${mcp.cors.allowed-origins}")
private List<String> allowedOrigins;

@Bean
@ConditionalOnProperty(name = "http.security.enabled", havingValue = "true", matchIfMissing = true)
SecurityFilterChain securityFilterChain(HttpSecurity http) throws Exception {
Expand Down Expand Up @@ -80,9 +83,19 @@ SecurityFilterChain unsecured(HttpSecurity http) throws Exception {

public CorsConfigurationSource corsConfigurationSource() {
CorsConfiguration configuration = new CorsConfiguration();
configuration.setAllowedOriginPatterns(List.of("*"));
configuration.setAllowedMethods(List.of("*"));
configuration.setAllowedHeaders(List.of("*"));
// Use the strict setAllowedOrigins API (not setAllowedOriginPatterns) so the
// browser-spec rule that wildcards cannot be combined with credentials is
// enforced.
// Origins are configurable via the mcp.cors.allowed-origins property
// (env: MCP_CORS_ALLOWED_ORIGINS) and default to the MCP Inspector's local
// proxy.
configuration.setAllowedOrigins(allowedOrigins);
// Only the HTTP methods used by the MCP Streamable HTTP transport.
configuration.setAllowedMethods(List.of("GET", "POST", "DELETE", "OPTIONS"));
// Only the headers the MCP specification requires for the Streamable HTTP
// transport.
configuration.setAllowedHeaders(
List.of("Authorization", "Content-Type", "Mcp-Session-Id", "MCP-Protocol-Version", "Last-Event-ID"));
configuration.setAllowCredentials(true);

UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
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4 changes: 4 additions & 0 deletions src/main/resources/application-http.properties
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Expand Up @@ -28,6 +28,10 @@ spring.security.oauth2.resourceserver.jwt.issuer-uri=${OAUTH2_ISSUER_URI:https:/
# in any environment reachable from the network is unsafe; the MCP Authorization
# specification requires HTTP-based MCP servers to authenticate.
http.security.enabled=${HTTP_SECURITY_ENABLED:true}
# Comma-separated list of allowed CORS origins for the MCP HTTP endpoint.
# Defaults to MCP Inspector's local proxy. Add additional origins (browser-based
# MCP clients, internal dashboards) as needed. Do NOT use "*" with credentials.
mcp.cors.allowed-origins=${MCP_CORS_ALLOWED_ORIGINS:http://localhost:6274,http://127.0.0.1:6274}
# observability
management.endpoints.web.exposure.include=health,sbom,metrics,info,loggers,prometheus
# Enable @Observed annotation support for custom spans
Expand Down
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