CVE-2021-34470: microsoft exchange_server
CVSS: 8.0v3.1HighModified
Published 14-07-2021Last modified 10-08-2026
Vulnerability summary
CVE-2021-34470 is a high (CVSS 8.0) vulnerability in microsoft exchange_server. EPSS estimates a 4.38% chance of exploitation in the next 30 days, higher than 91.1% of scored vulnerabilities.
CVSS score
8.0/10
010
High · v3.1 (CVE.org)EPSS score
4.38%
0%100%
Low · 0.00 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Timeline
- 14-07-2021PublishedVulnerability first disclosed.
- 10-08-2026Last modifiedVulnerability information updated.
Description
Microsoft Exchange Server Elevation of Privilege Vulnerability
CVSS metrics
3 scores · 2 sources · 2 versionsHigh 8.0Preferred score · CVE.org (CNA)
CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:CSourcesAll 2 agree
- NVDNIST8.0HighCVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Medium 5.2Preferred score · NVD (NIST)
AV:A/AC:L/Au:S/C:P/I:P/A:PSourcesSingle source
EPSS trend
Probability
4.38%
Chance of exploitation in the next 30 days
Percentile
91%
Versus all other CVEs
30-day change
0.00 pp
From 4.38% on 20-09-2026
20-09-202620-10-2026
EPSS score4.38%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeNo weakness data has been published for this record.
Affected systems
Microsoft4 products
- exchange_server2013:cumulative_update_23 | 2016:cumulative_update_21 | 2019:cumulative_update_10
- microsoft exchange server 2013 cumulative update 23≥ 15.00.0, < 15.00.1497.023
- microsoft exchange server 2016 cumulative update 21≥ 15.01.0, < 15.01.2308.008
- microsoft exchange server 2019 cumulative update 10≥ 15.02.0, < 15.02.0922.007
1 vendor · 4 products
References
3 links
- portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-34470X Refsource MISCX TransferredPatchVendor Advisory