CVE-2026-55005: Microsoft Exchange Server Remote Code Execution Vulnerability

Published Jul 14, 2026
·
Updated

Heap-based buffer overflow in Microsoft Exchange Server allows an authorized attacker to execute code over a network.

Other sources

Microsoft Exchange Server Remote Code Execution Vulnerability

— Microsoft

Affected Software

8 affected componentsFixes available
Microsoft Exchange Server 2019=15
15.02.1748.048
Microsoft Exchange Server Subscription Edition RTM<15.02.2562.045
15.02.2562.045
Microsoft Exchange Server 2016=23
15.01.2507.071
Microsoft Exchange Server 2019=14
15.02.1544.043
Microsoft Exchange Server=2016-cumulative_update_23
Microsoft Exchange Server=2019-cumulative_update_14
Microsoft Exchange Server=2019-cumulative_update_15
Microsoft Exchange Server Subscription Edition<15.02.2562.045

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 15.02.1748.048Patch KB5103213
  2. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 15.02.2562.045Patch KB5103212
  3. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 15.01.2507.071Patch KB5103215
  4. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 15.02.1544.043Patch KB5103214

Event History

Jul 14, 2026
CVE Published
via Microsoft·02:00 PM
Data Sourced
via Microsoft·02:00 PM
DescriptionSeverityWeakness
Data Sourced
via Microsoft·02:00 PM
Affected Software
Updated
via Microsoft·02:00 PM
Description
CVE Published
via MITRE·05:04 PM
Data Sourced
via MITRE·05:04 PM
DescriptionSeverity
Data Sourced
via NVD·05:17 PM
DescriptionSeverityWeaknessAffected Software
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Frequently Asked Questions

1

What is the severity of CVE-2026-55005?

CVE-2026-55005 has a high severity rating of 8.8.

2

How can I fix CVE-2026-55005?

To fix CVE-2026-55005, apply the latest updates and patches provided by Microsoft for Exchange Server.

3

What systems are affected by CVE-2026-55005?

CVE-2026-55005 affects Microsoft Exchange Server 2019, Microsoft Exchange Server Subscription Edition RTM, and Microsoft Exchange Server 2016.

4

What type of vulnerability is CVE-2026-55005?

CVE-2026-55005 is classified as a heap-based buffer overflow vulnerability.

5

What can an attacker achieve by exploiting CVE-2026-55005?

An authorized attacker can execute arbitrary code over a network by exploiting CVE-2026-55005.

Company

Resources

Contact

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