CVE-2026-118157 · Vendor
NO FIX YET
Microsoft Exchange Server has weak authentication that lets an attacker who already holds a valid account over the network raise their privileges. The sources give no fixed version, no exploitation evidence, and no further technical detail.
first public Nov 10, 2026 · 1 source
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Organizations running Microsoft Exchange Server on-premises are the ones exposed, since the flaw is in the server rather than a library. Attackers need a valid account first, so mailboxes and directories with many accounts carry more risk. The sources do not state which Exchange versions or configurations are affected, so teams should check Microsoft's advisory before deciding who can skip it.
Not affected if exchange-online
Who cares exchange-server, microsoft-exchange, on-premises
Unknown from the sources. In the analyst’s queue.
No fix yet, per the sources.
Weak authentication in Microsoft Exchange Server allows an authorized attacker to elevate privileges over a network.
This page as .md · .json · CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
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