CVE-2021-26857
Published Mar 3, 2021
Last updated 5 months ago
- Description
- Microsoft Exchange Server Remote Code Execution Vulnerability
- Source
- secure@microsoft.com
- NVD status
- Analyzed
- Products
- exchange_server
CVSS 3.1
- Type
- Secondary
- Base score
- 7.8
- Impact score
- 5.9
- Exploitability score
- 1.8
- Vector string
- CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- Severity
- HIGH
CVSS 2.0
- Type
- Primary
- Base score
- 6.8
- Impact score
- 6.4
- Exploitability score
- 8.6
- Vector string
- AV:N/AC:M/Au:N/C:P/I:P/A:P
Data from CISA
- Vulnerability name
- Microsoft Exchange Server Remote Code Execution Vulnerability
- Exploit added on
- Nov 3, 2021
- Exploit action due
- Apr 16, 2021
- Required action
- Apply updates per vendor instructions.
- Hype score
- Not currently trending
Ransomware vulns with highest exploit likelihood ⬆️ (past 30d): - CVE-2025-61882 (Oracle E-Busine..) +191397.67% - CVE-2021-27878 (Veritas Veritas..) +167.85% - CVE-2021-27877 (Veritas Veritas..) +151.55% - CVE-2021-27102 (Accellion File ..) +38.22% - CVE-2021-26857 (Exchang
@DefusedCyber
20 Oct 2025
1792 Impressions
7 Retweets
18 Likes
6 Bookmarks
1 Reply
1 Quote
Ransomware vulns with highest exploit likelihood ⬆️ (past 30d): - CVE-2025-61882 (Oracle E-Busine..) +184037.21% - CVE-2021-26857 (Exchange On-Pre..) +384.58% - CVE-2021-27878 (Veritas Veritas..) +202.15% - CVE-2021-27877 (Veritas Veritas..) +183.71% - CVE-2021-27102 (Accell
@DefusedCyber
13 Oct 2025
12527 Impressions
14 Retweets
102 Likes
47 Bookmarks
1 Reply
1 Quote
Ransomware vulns with highest exploit likelihood ⬆️ (past 30d): - CVE-2021-26857 (Exchange On-Pre..) +210.76% - CVE-2022-26500 (Veeam Backup & ..) +24.70% - CVE-2023-27532 (Veeam Backup & ..) +17.62% - CVE-2022-41352 (Zimbra Zimbra C..) +16.52% - CVE-2019-5591 (Forti
@DefusedCyber
29 Sept 2025
33921 Impressions
50 Retweets
256 Likes
138 Bookmarks
3 Replies
2 Quotes
Ransomware vulns with highest exploit likelihood ⬆️ (past 30d): - CVE-2021-26857 (Exchange On-Pre..) +210.76% - CVE-2022-26500 (Veeam Backup & ..) +24.70% - CVE-2015-2291 (IQVW32.sys (BYO..) +22.80% - CVE-2023-27532 (Veeam Backup & ..) +17.62% - CVE-2021-27876 (Verit
@DefusedCyber
22 Sept 2025
10416 Impressions
13 Retweets
89 Likes
63 Bookmarks
1 Reply
1 Quote
Ransomware vulns with highest exploit likelihood ⬆️ (past 30d): - CVE-2025-53770 (SharePoint..) +86627.50% - CVE-2019-5591 (FortiOS..) +44.14% - CVE-2021-26857 (Exchange On-Pre..) +32.05% - CVE-2024-42057 (Zyxel Firewall..) +29.73% - CVE-2021-27101 (Accellion File ..) +23.48
@DefusedCyber
11 Aug 2025
652 Impressions
2 Retweets
8 Likes
4 Bookmarks
0 Replies
1 Quote
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