7.8
High
Exploited
· ransomware
CVE-2021-26857 Microsoft Exchange Server Remote Code Execution Vulnerability
Active exploitation observed
· CISA KEV catalogue
Required action
Apply updates per vendor instructions.
Ransomware campaigns
Known to be used
Weakness
CWE-502
Description
Microsoft Exchange Server Remote Code Execution Vulnerability
Affected products and versions
| Product | Affected versions | Fixed in |
|---|---|---|
| Microsoft Exchange Server 2016 Cumulative Update 19 15.01 | 15.01.0 → < 15.01.2176.009 | 15.01.2176.009 |
| Microsoft Exchange Server 2019 Cumulative Update 8 15.02 | 15.02.0 → < 15.02.0792.010 | 15.02.0792.010 |
| Microsoft Exchange Server 2019 15.02 | 15.02.0 → < 15.02.0221.018 | 15.02.0221.018 |
| Microsoft Exchange Server 2013 Cumulative Update 22 15.00 | 15.00.0 → < 15.00.1473.006 | 15.00.1473.006 |
| Microsoft Exchange Server 2019 Cumulative Update 2 15.02 | 15.02.0 → < 15.02.0397.011 | 15.02.0397.011 |
| Microsoft Exchange Server 2016 Cumulative Update 13 15.01 | 15.01.0 → < 15.01.1779.008 | 15.01.1779.008 |
| Microsoft Exchange Server 2013 Cumulative Update 23 15.00 | 15.00.0 → < 15.00.1497.012 | 15.00.1497.012 |
| Microsoft Exchange Server 2019 Cumulative Update 3 15.02 | 15.02.0 → < 15.02.0464.015 | 15.02.0464.015 |
| Microsoft Exchange Server 2016 Cumulative Update 14 15.01 | 15.01.0 → < 15.01.1847.012 | 15.01.1847.012 |
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| Product | Affected versions | Fixed in |
|---|---|---|
| Microsoft Exchange Server 2019 Cumulative Update 4 15.02 | 15.02.0 → < 15.02.0659.012 | 15.02.0659.012 |
| Microsoft Exchange Server 2016 Cumulative Update 15 15.01 | 15.01.0 → < 15.01.1913.012 | 15.01.1913.012 |
| Microsoft Exchange Server 2019 Cumulative Update 5 15.02 | 15.02.0 → < 15.02.0595.008 | 15.02.0595.008 |
| Microsoft Exchange Server 2019 Cumulative Update 6 15.02 | 15.02.0 → < 15.02.0529.013 | 15.02.0529.013 |
| Microsoft Exchange Server 2016 Cumulative Update 16 15.01 | 15.01.0 → < 15.01.1979.008 | 15.01.1979.008 |
| Microsoft Exchange Server 2016 Cumulative Update 17 15.01 | 15.01.0 → < 15.01.2044.013 | 15.01.2044.013 |
| Microsoft Exchange Server 2019 Cumulative Update 7 15.02 | 15.02.0 → < 15.02.0721.013 | 15.02.0721.013 |
| Microsoft Exchange Server 2016 Cumulative Update 18 15.01 | 15.01.0 → < 15.01.2106.013 | 15.01.2106.013 |
| Microsoft Exchange Server 2010 Service Pack 3 14.0 | 14.0.0.0 → < 14.03.0513.000 | 14.03.0513.000 |
| Microsoft Exchange Server 2013 Service Pack 1 15.00 | 15.00.0 → < 15.00.0847.064 | 15.00.0847.064 |
| Microsoft Exchange Server 2013 Cumulative Update 21 15.00 | 15.00.0 → < 15.00.1395.012 | 15.00.1395.012 |
| Microsoft Exchange Server 2016 Cumulative Update 12 15.01 | 15.01.0 → < 15.01.1713.010 | 15.01.1713.010 |
| Microsoft Exchange Server 2016 Cumulative Update 8 15.01 | 15.01.0 → < 15.01.1415.010 | 15.01.1415.010 |
| Microsoft Exchange Server 2019 Cumulative Update 1 15.01 | earliest → < 15.01.1979.006 | 15.01.1979.006 |
| Microsoft Exchange Server 2016 Cumulative Update 9 15.01 | 15.01.0 → < 15.01.1466.016 | 15.01.1466.016 |
| Microsoft Exchange Server 2016 Cumulative Update 10 15.01 | 15.01.0 → < 15.01.1531.012 | 15.01.1531.012 |
| Microsoft Exchange Server 2016 Cumulative Update 11 15.01 | 15.01.0 → < 15.01.1591.018 | 15.01.1591.018 |
References
- Microsoft Exchange Server Remote Code Execution Vulnerability msrc.microsoft.com
Timeline
- Published
- Added to the KEV catalogue
- Last modified
Other CVEs of Microsoft Exchange Server 2016 Cumulative Update 19
The 19 CVEs of Microsoft Exchange Server 2016 Cumulative Update 19 →
CVE-2021-34523
Microsoft Exchange Server Privilege Escalation Vulnerability
9.0
Critical
CVE-2021-34473
Microsoft Exchange Server Remote Code Execution Vulnerability
9.1
Critical
CVE-2021-33766
Microsoft Exchange Server Information Disclosure
7.3
High
CVE-2021-31209
Microsoft Exchange Server Spoofing Vulnerability
6.5
Medium