CVE-2026-87696

What it is

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

At a glance

Exploitability

Can be exploited over the network with a low-privilege account. High risk of data exposure, data tampering, service disruption.

Exploit odds

0.4% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-10-13 19:21 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-10-27 17:01 UTC Last updatedMost recent change to the record

Details

Published

2026-10-13 19:21 UTC

Last modified

2026-10-27 17:01 UTC

Exploit probability

0.4% · EPSS, next 30 days

Weakness

CWE-347

Record status

Analyzed

Affected

• Microsoft Exchange Server 2016
• Microsoft Exchange Server 2019
• Microsoft Exchange Server Subscription Edition < 15.02.2562.056

Attack profile CVSS 3.1 · 7.5

Attack vector

Network

Complexity

High

Privileges needed

Low

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High