Webpack

Webpack is a module bundler. From version 5.49.0 to before 5.104.1, 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). This issue has been patched in version 5.104.1.

Published: 2026-02-05T23:08:01.102Z
Updated: 2026-02-06T20:26:59.798Z

Webpack is a module bundler. From version 5.49.0 to before 5.104.0, when experiments.buildHttp is enabled, webpack’s HTTP(S) resolver (HttpUriPlugin) enforces allowedUris only for the initial URL, but does not re-validate allowedUris after following HTTP 30x redirects. As a result, an import that appears restricted to a trusted allow-list can be redirected to HTTP(S) URLs outside the allow-list. This is a policy/allow-list bypass that enables build-time SSRF behavior (requests from the build machine to internal-only endpoints, depending on network access) and untrusted content inclusion in build outputs (redirected content is treated as module source and bundled). This issue has been patched in version 5.104.0.

Published: 2026-02-05T23:08:13.214Z
Updated: 2026-02-06T19:29:14.352Z

Webpack is a module bundler. Its main purpose is to bundle JavaScript files for usage in a browser, yet it is also capable of transforming, bundling, or packaging just about any resource or asset. The webpack developers have discovered a DOM Clobbering vulnerability in Webpack’s `AutoPublicPathRuntimeModule`. The DOM Clobbering gadget in the module can lead to cross-site scripting (XSS) in web pages where scriptless attacker-controlled HTML elements (e.g., an `img` tag with an unsanitized `name` attribute) are present. Real-world exploitation of this gadget has been observed in the Canvas LMS which allows a XSS attack to happen through a javascript code compiled by Webpack (the vulnerable part is from Webpack). DOM Clobbering is a type of code-reuse attack where the attacker first embeds a piece of non-script, seemingly benign HTML markups in the webpage (e.g. through a post or comment) and leverages the gadgets (pieces of js code) living in the existing javascript code to transform it into executable code. This vulnerability can lead to cross-site scripting (XSS) on websites that include Webpack-generated files and allow users to inject certain scriptless HTML tags with improperly sanitized name or id attributes. This issue has been addressed in release version 5.94.0. All users are advised to upgrade. There are no known workarounds for this issue.

Published: 2024-08-27T17:07:16.285Z
Updated: 2025-01-09T17:41:35.616Z

Webpack 5 before 5.76.0 does not avoid cross-realm object access. ImportParserPlugin.js mishandles the magic comment feature. An attacker who controls a property of an untrusted object can obtain access to the real global object.

Published: 2023-03-13T00:00:00.000Z
Updated: 2025-02-27T19:54:32.541Z