Vulnerability Intelligence Report
Microsoft Exchange Server Remote Code Execution Vulnerability
CVE-2021-26857
Microsoft Exchange Server Remote Code Execution Vulnerability
CISA KEV
SSVC: Active Exploitation
CVSS Base Score
7.8
HIGH
Exploitability:1.9
Impact Score:5.9
EPSS Probability:94.01%
Executive Threat Verdict
Evaluating...
Evaluating Threat Landscape...
Assessing known weaponization, exploitation telemetry, and federal advisories.
Attack Surface
—
Authentication
—
Weaponization
—
SSVC Action
—
Weaknesses (CWE)
CWE-502 ↗CWE-502 Deserialization of Untrusted Data
Affected Products & Versions
| Vendor | Product | Affected Versions |
|---|---|---|
| Microsoft | Microsoft Exchange Server 2010 Service Pack 3 | 14.0.0.0 < 14.03.0513.000 (affected) |
| Microsoft | Microsoft Exchange Server 2013 Cumulative Update 21 | 15.00.0 < 15.00.1395.012 (affected) |
| Microsoft | Microsoft Exchange Server 2013 Cumulative Update 22 | 15.00.0 < 15.00.1473.006 (affected) |
| Microsoft | Microsoft Exchange Server 2013 Cumulative Update 23 | 15.00.0 < 15.00.1497.012 (affected) |
| Microsoft | Microsoft Exchange Server 2013 Service Pack 1 | 15.00.0 < 15.00.0847.064 (affected) |
| Microsoft | Microsoft Exchange Server 2016 Cumulative Update 10 | 15.01.0 < 15.01.1531.012 (affected) |
| Microsoft | Microsoft Exchange Server 2016 Cumulative Update 11 | 15.01.0 < 15.01.1591.018 (affected) |
| Microsoft | Microsoft Exchange Server 2016 Cumulative Update 12 | 15.01.0 < 15.01.1713.010 (affected) |
| Microsoft | Microsoft Exchange Server 2016 Cumulative Update 13 | 15.01.0 < 15.01.1779.008 (affected) |
| Microsoft | Microsoft Exchange Server 2016 Cumulative Update 14 | 15.01.0 < 15.01.1847.012 (affected) |
| Microsoft | Microsoft Exchange Server 2016 Cumulative Update 15 | 15.01.0 < 15.01.1913.012 (affected) |
| Microsoft | Microsoft Exchange Server 2016 Cumulative Update 16 | 15.01.0 < 15.01.1979.008 (affected) |
| Microsoft | Microsoft Exchange Server 2016 Cumulative Update 17 | 15.01.0 < 15.01.2044.013 (affected) |
| Microsoft | Microsoft Exchange Server 2016 Cumulative Update 18 | 15.01.0 < 15.01.2106.013 (affected) |
| Microsoft | Microsoft Exchange Server 2016 Cumulative Update 19 | 15.01.0 < 15.01.2176.009 (affected) |
| Microsoft | Microsoft Exchange Server 2016 Cumulative Update 8 | 15.01.0 < 15.01.1415.010 (affected) |
| Microsoft | Microsoft Exchange Server 2016 Cumulative Update 9 | 15.01.0 < 15.01.1466.016 (affected) |
| Microsoft | Microsoft Exchange Server 2019 | 15.02.0 < 15.02.0221.018 (affected) |
| Microsoft | Microsoft Exchange Server 2019 Cumulative Update 1 | 15.02.0 < 15.01.1979.006 (affected) |
| Microsoft | Microsoft Exchange Server 2019 Cumulative Update 2 | 15.02.0 < 15.02.0397.011 (affected) |
| Microsoft | Microsoft Exchange Server 2019 Cumulative Update 3 | 15.02.0 < 15.02.0464.015 (affected) |
| Microsoft | Microsoft Exchange Server 2019 Cumulative Update 4 | 15.02.0 < 15.02.0659.012 (affected) |
| Microsoft | Microsoft Exchange Server 2019 Cumulative Update 5 | 15.02.0 < 15.02.0595.008 (affected) |
| Microsoft | Microsoft Exchange Server 2019 Cumulative Update 6 | 15.02.0 < 15.02.0529.013 (affected) |
| Microsoft | Microsoft Exchange Server 2019 Cumulative Update 7 | 15.02.0 < 15.02.0721.013 (affected) |
| Microsoft | Microsoft Exchange Server 2019 Cumulative Update 8 | 15.02.0 < 15.02.0792.010 (affected) |
References & Technical Advisories
No reference links found.
Threat Intelligence Signals
Identity & Timeline
| Status | PUBLISHED |
| Assigning Authority | Microsoft Corporation · Vendor · USA |
| Reserved | 2021-02-08T00:00:00 |
| Published | 2021-03-02T23:55:26 |
| Patch Date | 2021-03-02 |
| Last Updated | 2026-08-19T16:30:15 |
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