Double Free in Microsoft Exchange Server

Publication date: 2026-09-08

Last updated on: 2026-10-05

Assigner: Microsoft Corporation

Description

Double free in Microsoft Exchange Server allows an unauthorized attacker to execute code over a network.

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published

2026-09-08

Last Modified

2026-10-05

Generated

2026-10-19

AI Q&A

2026-09-09

EPSS Evaluated

2026-10-18

NVD

CVE-2026-55007

Affected Vendors & Products

Vendor	Product	Version / Range
microsoft	exchange_server	2019
microsoft	exchange_server	2019
microsoft	exchange_server_subscription_edition	to 15.02.2562.049 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-415	The product calls free() twice on the same memory address.

Attack-Flow Graph

Executive Summary

This vulnerability is a double free issue in Microsoft Exchange Server. A double free occurs when a program frees the same memory block twice, which can lead to memory corruption and allow an attacker to execute arbitrary code remotely over a network.

Impact Analysis

An unauthorized attacker could exploit this flaw to run malicious code on your Exchange Server. This could result in unauthorized access to sensitive data, installation of malware, or disruption of email services. The high CVSS score indicates significant risk.

Mitigation Strategies

Apply the latest security updates from Microsoft for Exchange Server as soon as possible to patch the double free vulnerability.

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