6.5

CVE-2021-42305: microsoft exchange_server

CVSS: 6.5v3.1MediumModified
Published 10-11-2021Last modified 19-08-2026
Open JSON

Vulnerability summary

CVE-2021-42305 is a medium (CVSS 6.5) vulnerability in microsoft exchange_server. EPSS estimates a 7.87% chance of exploitation in the next 30 days, higher than 94.6% of scored vulnerabilities.

Overall risk
28/100
0100
Medium · default modelHow is this calculated?
CVSS score
6.5/10
010
Medium · v3.1 (CVE.org)
EPSS score
7.87%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 10-11-2021
    PublishedVulnerability first disclosed.
  2. 19-08-2026
    Last modifiedVulnerability information updated.

Description

Microsoft Exchange Server Spoofing Vulnerability

CVSS metrics

3 scores · 2 sources · 2 versions

EPSS trend

Probability

7.87%

Chance of exploitation in the next 30 days

Percentile

95%

Versus all other CVEs

30-day change

0.00 pp

From 7.87% on 20-09-2026

20-09-202620-10-2026
EPSS score
7.87%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

No weakness data has been published for this record.

Affected systems

Microsoft6 products

1 vendor · 6 products

References

2 links