CVE-2026
We use optional cookies to improve your experience on our websites, such as through social media connections, and to display personalized advertising based on your online activity. If you reject optional cookies, only cookies necessary to provide you the services will be used. You may change your selection by clicking “Manage Cookies” at the bottom of the page. Privacy Statement Third-Party Cookies
Released: Sep 8, 2026
Please see Common Vulnerability Scoring System for more information on the definition of these metrics.
Authorization bypass through user-controlled key in Microsoft Exchange Server allows an authorized attacker to perform tampering over a network.
The following table provides an exploitability assessment for this vulnerability at the time of original publication.
According to the CVSS metrics, successful exploitation of this vulnerability could lead to major loss of integrity (I:H). What does that mean for this vulnerability?
An authenticated attacker could replace valid file content with specially crafted file content.
According to the CVSS metric, privileges required is low (PR:L). What does that mean for this vulnerability?
Any authenticated attacker could trigger this vulnerability. It does not require admin or other elevated privileges.
To determine the support lifecycle for your software, see the Microsoft Support Lifecycle .
Information published.
The full story
This article is one source in a clustered incident — the cluster page carries the summary, timeline and every other outlet covering it.
