CVE-2021-26896: microsoft windows_server_2008
CVSS: 7.5v3.1HighModified
Published 11-03-2021Last modified 19-08-2026
Vulnerability summary
CVE-2021-26896 is a high (CVSS 7.5) vulnerability in microsoft windows_server_2008. EPSS estimates a 7.85% chance of exploitation in the next 30 days, higher than 94.6% of scored vulnerabilities.
CVSS score
7.5/10
010
High · v3.1 (CVE.org)EPSS score
7.85%
0%100%
Low · +0.49 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Timeline
- 11-03-2021PublishedVulnerability first disclosed.
- 19-08-2026Last modifiedVulnerability information updated.
Description
Windows DNS Server Denial of Service Vulnerability
CVSS metrics
3 scores · 2 sources · 2 versionsHigh 7.5Preferred score · CVE.org (CNA)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:CSourcesAll 2 agree
- NVDNIST7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Medium 5.0Preferred score · NVD (NIST)
AV:N/AC:L/Au:N/C:N/I:N/A:PSourcesSingle source
EPSS trend
Probability
7.85%
Chance of exploitation in the next 30 days
Percentile
95%
Versus all other CVEs
30-day change
+0.49 pp
From 7.35% on 21-09-2026
21-09-202621-10-2026
EPSS score7.85%
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
Microsoft16 products
- windows_server_2008r2:sp1 | sp2
- windows server 2008 r2 service pack 1≥ 6.1.7601.0, < 6.1.7601.24566
- windows server 2008 r2 service pack 1 (server core installation)≥ 6.1.7601.0, < 6.1.7601.24566
- windows server 2008 service pack 2≥ 6.0.6003.0, < 6.0.6003.21070
- windows server 2008 service pack 2 (server core installation)≥ 6.0.6003.0, < 6.0.6003.21070
1 vendor · 16 products
References
2 links- portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-26896X Refsource MISCX TransferredPatchVendor Advisory