CVE-2026-87696: Improper verification of cryptographic signature in Microsoft Exchange Server allows an authorized attacker to elevate privileges over a network.

PriorityP351high7.5CVSS 3.1

AVNACHPRLUINSUCHIHAH

EPSS

0.38%

30.6th percentile

Improper verification of cryptographic signature in Microsoft Exchange Server allows an authorized attacker to elevate privileges over a network.

Affected

4 ranges

Vendor	Product	Version range	Fixed in
microsoft	microsoft_exchange_server_2016_cumulative_update_23	>= 15.01.0.0 < 15.01.2507.077	15.01.2507.077
microsoft	microsoft_exchange_server_2019_cumulative_update_14	>= 15.02.0.0 < 15.02.1544.050	15.02.1544.050
microsoft	microsoft_exchange_server_2019_cumulative_update_15	>= 15.02.0.0 < 15.02.1748.055	15.02.1748.055
microsoft	microsoft_exchange_server_subscription_edition_rtm	>= 15.02.0.0 < 15.02.2562.056	15.02.2562.056

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