@@ -0,0 +1,5 @@
+---
+"webpack": patch
+---
+
+Fix stack overflows in ESM library star reexport cycles with externals.
@@ -418,11 +418,14 @@ class ModuleLibraryPlugin extends AbstractLibraryPlugin {
 		const moduleRequests = new Set();
 		/** @type {Map<string, string | InlinedUsedName>} */
 		const unknownProvidedExports = new Map();
+		/** @type {Set<Module>} */
+		const visitedReexportModules = new Set();
 
 		/**
 		 * Resolves dynamic star reexport.
 		 * @param {Module} module the module
 		 * @param {boolean} isDynamicReexport if module is dynamic reexported
+		 * @returns {void}
 		 */
 		const resolveDynamicStarReexport = (module, isDynamicReexport) => {
 			for (const connection of moduleGraph.getOutgoingConnections(module)) {
@@ -446,7 +449,8 @@ class ModuleLibraryPlugin extends AbstractLibraryPlugin {
 						// Handle export * from 'external'
 						if (importedModule instanceof ExternalModule) {
 							moduleRequests.add(importedModule.userRequest);
-						} else {
+						} else if (!visitedReexportModules.has(importedModule)) {
+							visitedReexportModules.add(importedModule);
 							resolveDynamicStarReexport(importedModule, true);
 						}
 					}
 
@@ -0,0 +1,2 @@
+export * from "./library.js";
+export * from "external";
@@ -0,0 +1,7 @@
+import * as library from "./library.mjs";
+
+it("should preserve external and local exports through circular star reexports", () => {
+	expect(library.externalValue).toBe(42);
+	expect(library.localValue).toBe(1);
+	expect(Object.keys(library)).toEqual(["externalValue", "localValue"]);
+});
@@ -0,0 +1,2 @@
+export * from "./cycle.js";
+export * from "./local.js";
@@ -0,0 +1 @@
+export const localValue = 1;
@@ -0,0 +1,14 @@
+"use strict";
+
+module.exports = {
+	/**
+	 * @param {number} index configuration index
+	 * @returns {string} emitted test bundle
+	 */
+	findBundle(index) {
+		return `main${index}.mjs`;
+	},
+	modules: {
+		external: { externalValue: 42 }
+	}
+};
@@ -0,0 +1,22 @@
+"use strict";
+
+/** @type {import("../../../../").Configuration[]} */
+module.exports = [
+	{ type: "module", minimize: false },
+	{ type: "module", minimize: true },
+	{ type: "modern-module", minimize: false },
+	{ type: "modern-module", minimize: true }
+].map(({ type, minimize }, index) => ({
+	mode: minimize ? "production" : "development",
+	entry: {
+		main: "./index.js",
+		library: { import: "./library.js", library: { type } }
+	},
+	output: { module: true, filename: `[name]${index}.mjs` },
+	externalsType: "module",
+	externals: {
+		"./library.mjs": `./library${index}.mjs`,
+		external: "external"
+	},
+	optimization: { minimize }
+}));
-Original file line number
+Diff line change
@@ @@ -0,0 +1,5 @@ @@
 +---
 +"webpack": patch
 +---
++
 +Fix stack overflows in ESM library star reexport cycles with externals.
Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,2 @@`
	`1`	`+export * from "./library.js";`
	`2`	`+export * from "external";`
Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,2 @@`
	`1`	`+export * from "./cycle.js";`
	`2`	`+export * from "./local.js";`