Advisoriesby IbisMicrosoftCVE-2026-55009
Microsoft Exchange Server: unsafe deserialization
Fix: upgrade to 15.01.2507.071 or later (4 fixed versions below)
Deserialization of untrusted data in Microsoft Exchange Server allows an authorized attacker to elevate privileges locally.
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:L/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-502