An information disclosure vulnerability exists when the Microsoft Edge Fetch API incorrectly handles a filtered response type. An attacker could use the vulnerability to read the URL of a cross-origin request. Websites that that do not securely populate the URL with confidential information could allow information to be disclosed to an attacker.
To exploit the vulnerability, in a web-based attack scenario, an attacker could host a website in an attempt to exploit the vulnerability. In addition, the user must be logged on to a website that does not securely populate URLs with confidential information. However, in all cases an attacker would have no way to force a user to view the attacker-controlled content. Instead, an attacker would have to convince the user to take action. For example, an attacker could trick a user into clicking a link that takes them to the attacker's site.
The update addresses the vulnerability by changing how the Fetch API in Microsoft Edge handles specific filtered response types.
## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Microsoft | Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1803 for 32-bit Systems | 17134.285 | [KB4457128](https://patchblox.com/security/data/fix/microsoft/kb4457128.md) | Sep 11, 2018 | | Microsoft | Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1803 for x64-based Systems | 17134.285 | [KB4457128](https://patchblox.com/security/data/fix/microsoft/kb4457128.md) | Sep 11, 2018 | --- Data as of 2026-11-08T00:53:09Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo Free to use with attribution: show "Data: Patchblox Patch Radar" with a link to https://patchblox.com/security/patch-radar. Terms, including what needs a written agreement: https://patchblox.com/security/patch-radar/use-the-data Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.