An information disclosure vulnerability exists in the way that affected Microsoft browsers handle cross-origin requests. An attacker who successfully exploited this vulnerability could determine the origin of all of the web pages in the affected browser.
In a web-based attack scenario, an attacker could host a website that is used to attempt to exploit the vulnerability. Additionally, compromised websites and websites that accept or host user-provided content could contain specially crafted content that could be used to exploit the vulnerability. However, in all cases an attacker would have no way to force users to view attacker-controlled content. Instead, an attacker would have to convince users to take action. For example, an attacker could trick users into clicking a link that takes them to the attacker's site.
The security update addresses the vulnerability by correcting how affected browsers handle cross-origin resources.
## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Microsoft | Internet Explorer 11 on Windows 10 Version 1607 for 32-bit Systems | | [KB3189866](https://patchblox.com/security/data/fix/microsoft/kb3189866.md) | Sep 13, 2016 | | Microsoft | Internet Explorer 11 on Windows 10 Version 1607 for x64-based Systems | | [KB3189866](https://patchblox.com/security/data/fix/microsoft/kb3189866.md) | Sep 13, 2016 | | Microsoft | Internet Explorer 11 on Windows 10 for 32-bit Systems | 10240.17113 | [KB3185611](https://patchblox.com/security/data/fix/microsoft/kb3185611.md) | Sep 13, 2016 | | Microsoft | Internet Explorer 11 on Windows 10 for x64-based Systems | 10240.17113 | [KB3185611](https://patchblox.com/security/data/fix/microsoft/kb3185611.md) | Sep 13, 2016 | | Microsoft | Internet Explorer 11 on Windows 8.1 for 32-bit systems | | [KB3185319](https://patchblox.com/security/data/fix/microsoft/kb3185319.md) | Sep 13, 2016 | | Microsoft | Internet Explorer 11 on Windows 8.1 for x64-based systems | | [KB3185319](https://patchblox.com/security/data/fix/microsoft/kb3185319.md) | Sep 13, 2016 | | Microsoft | Internet Explorer 11 on Windows RT 8.1 | | [KB3185319](https://patchblox.com/security/data/fix/microsoft/kb3185319.md) | Sep 13, 2016 | | Microsoft | Internet Explorer 11 on Windows Server 2012 R2 | | [KB3185319](https://patchblox.com/security/data/fix/microsoft/kb3185319.md) | Sep 13, 2016 | | Microsoft | Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1511 for 32-bit Systems | 10586.589 | [KB3185614](https://patchblox.com/security/data/fix/microsoft/kb3185614.md) | Sep 13, 2016 | | Microsoft | Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1511 for x64-based Systems | 10586.589 | [KB3185614](https://patchblox.com/security/data/fix/microsoft/kb3185614.md) | Sep 13, 2016 | | Microsoft | Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1607 for 32-bit Systems | | [KB3189866](https://patchblox.com/security/data/fix/microsoft/kb3189866.md) | Sep 13, 2016 | | Microsoft | Microsoft Edge (EdgeHTML-based) on Windows 10 Version 1607 for x64-based Systems | | [KB3189866](https://patchblox.com/security/data/fix/microsoft/kb3189866.md) | Sep 13, 2016 | | Microsoft | Microsoft Edge (EdgeHTML-based) on Windows 10 for 32-bit Systems | 10240.17113 | [KB3185611](https://patchblox.com/security/data/fix/microsoft/kb3185611.md) | Sep 13, 2016 | | Microsoft | Microsoft Edge (EdgeHTML-based) on Windows 10 for x64-based Systems | 10240.17113 | [KB3185611](https://patchblox.com/security/data/fix/microsoft/kb3185611.md) | Sep 13, 2016 | --- Data as of 2026-11-07T06:34:28Z 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