CVE-2021-26896 Windows DNS Server Denial of Service Vulnerability

What is CVE-2021-26896?

CVE-2021-26896 is a high-severity denial of service vulnerability in Microsoft Windows Server 2008, published on 11 Mar 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

Windows DNS Server Denial of Service Vulnerability

Which versions are affected by CVE-2021-26896?

It affects 4 products.

Products include Microsoft Windows Server 2008, Microsoft Windows Server 2012, Microsoft Windows Server 2016, Microsoft Windows Server 2019.

How do I fix CVE-2021-26896?

No fix has been published for CVE-2021-26896 yet. Limit exposure of the affected software until one is available.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2021-26896 being exploited?

There is no known exploitation of CVE-2021-26896 in the wild and no public exploit code.

Other vulnerabilities in Microsoft Windows Server 2008

• CVE-2020-1350 Microsoft Windows DNS Server Remote Code Execution Exploited Critical 10.0
• CVE-2020-1040 Microsoft Hyper-V RemoteFX vGPU Remote Code Execution Exploited Critical 9.0
• CVE-2011-1966 Memory corruption in n/a Critical 10.0
• CVE-2010-0239 Memory corruption in n/a Critical 10.0
• CVE-2010-0240 Code injection in n/a Critical 10.0

All Microsoft Windows Server 2008 vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-fg89-fq65-83p5.