CVE-2026-45583Important
Microsoft Exchange Server Remote Code Execution Vulnerability
Assessment
Improper control of generation of code ('code injection') in Microsoft Exchange Server allows an unauthorized attacker to execute code over a network.
- Severity
- Important
- CVSS base score
- 7.5CVSS:3.1/
AV:N/ AC:H/ PR:N/ UI:R/ S:U/ C:H/ I:H/ A:H/ E:U/ RL:O/ RC:C - Impact
- Remote Code Execution
- EPSS, next 30 days
- 0.7%Higher than 51.2% of scored CVEs · FIRST model run 29 Sep 2026 · about EPSS
- Public exploit code
- No Nuclei template lists it
- Exploitability
- Exploitation Less Likely
- Publicly disclosed
- No
- Customer action
- Required: apply the update
- Component
- Microsoft Exchange Server
- Weakness
- CWE-94: Improper Control of Generation of Code ('Code Injection')
- Issued by
- Microsoft
- Published
- 9 Jun 2026 · June 2026
- Last revised
- 9 Jun 2026
Updates that fix it
4 KBs| KB | Type | Restart | Applies to | Other CVEs |
|---|---|---|---|---|
| KB5103212 | Security Update | Required | Microsoft Exchange Server Subscription Edition RTM | All CVEs in KB5103212 |
| KB5103213 | Security Update | Required | Microsoft Exchange Server 2019 Cumulative Update 15 | All CVEs in KB5103213 |
| KB5103214 | Security Update | Required | Microsoft Exchange Server 2019 Cumulative Update 14 | All CVEs in KB5103214 |
| KB5103215 | Security Update | Required | Microsoft Exchange Server 2016 Cumulative Update 23 | All CVEs in KB5103215 |