MicrosoftCVE-2026-55005
Microsoft Exchange Server: heap buffer overflow
High8.8CVE-2026-55005 · Published Jul 14, 2026 · updated Jul 24, 2026
Heap-based buffer overflow in Microsoft Exchange Server allows an authorized attacker to execute code over a network.
Affected versions
| Package | Affected | Fixed in |
|---|---|---|
| Microsoft Exchange Server 2016 Cumulative Update 23 Product | >= 15.01.0.0, < 15.01.2507.071 | 15.01.2507.071 |
| Microsoft Exchange Server 2019 Cumulative Update 14 Product | >= 15.02.0.0, < 15.02.1544.043 | 15.02.1544.043 |
| Microsoft Exchange Server 2019 Cumulative Update 15 Product | >= 15.02.0.0, < 15.02.1748.048 | 15.02.1748.048 |
| Microsoft Exchange Server Subscription Edition RTM Product | >= 15.02.0.0, < 15.02.2562.045 | 15.02.2562.045 |
Details and references
- CVSS 3.1
- CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Severity from
- the vendor (its own CVE record or advisory)
- Weakness
- CWE-122
More Microsoft advisories
All Microsoft| Date | Advisory | Severity | Fixed in |
|---|---|---|---|
| Jul 14 | Secret exfiltration vulnerability | High | 1.128.1 |
| Jul 14 | Workspace Trust Security Feature Bypass Vulnerability | High | 1.128.1 |
| Jul 14 | Remote Code Execution Vulnerability | High | 1.128.1 |
| Jul 14 | Microsoft .NET 8.0: unsafe deserialization | High7.8 | 8.0.29+9 more |
| Jul 14 | Microsoft .NET 8.0: code injection | High7.8 | 8.0.29+10 more |
| Jul 14 | Microsoft .NET 10.0: resource exhaustion | High7.5 | 10.0.10+5 more |