CVE-2021-26427
CRITICALCVSS 9/10EPSS 0.87%
Last modified
CVE-2021-26427 is a critical-severity vulnerability rated 9/10 on the CVSS scale. Microsoft Exchange Server Remote Code Execution Vulnerability. EPSS estimates a 0.87% chance of exploitation in the next 30 days.
Description
Microsoft Exchange Server Remote Code Execution Vulnerability
Metrics
CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Affected Software
| Vendor | Product | Versions | Update |
|---|---|---|---|
| Microsoft | Exchange Server | 2013 | Cumulative Update 23 |
| Microsoft | Exchange Server | 2016 | Cumulative Update 21 |
| Microsoft | Exchange Server | 2019 | Cumulative Update 10 |
References
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-26427Patch, Vendor Advisory
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-26427Patch, Vendor Advisory
Timeline
- Published
- Last Modified
- Status
- Modified
Frequently Asked Questions
What is CVE-2021-26427?
Microsoft Exchange Server Remote Code Execution Vulnerability
How severe is CVE-2021-26427?
CVE-2021-26427 has a CVSS score of 9/10 (CRITICAL severity). The EPSS model estimates a 0.87% probability of exploitation in the next 30 days.
How do I fix CVE-2021-26427?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.
How Strix Helps
- How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
- Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
- PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
- AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.
Related CVEs from 2021
- CVE-2021-26421Skype for Business and Lync Spoofing Vulnerability6.5
- CVE-2021-26422Skype for Business and Lync Remote Code Execution Vulnerabil…7.2
- CVE-2021-26423.NET Core and Visual Studio Denial of Service Vulnerability7.5
- CVE-2021-26424Windows TCP/IP Remote Code Execution Vulnerability9.9
- CVE-2021-26425Windows Event Tracing Elevation of Privilege Vulnerability7.8
- CVE-2021-26426Windows User Account Profile Picture Elevation of Privilege …7
- CVE-2021-26428Azure Sphere Information Disclosure Vulnerability4.4
- CVE-2021-26429Azure Sphere Elevation of Privilege Vulnerability7.7
- CVE-2021-26430Azure Sphere Denial of Service Vulnerability6
- CVE-2021-26431Windows Recovery Environment Agent Elevation of Privilege Vu…7.8
- CVE-2021-26432Windows Services for NFS ONCRPC XDR Driver Remote Code Execu…9.8
- CVE-2021-26433Windows Services for NFS ONCRPC XDR Driver Information Discl…7.5
Are you affected by CVE-2021-26427?
Run a free Strix scan to check your systems for this vulnerability.
Scan your code nowSource: NVD / NIST