CVE-2026-84008 .NET Denial of Service Vulnerability
An attacker can cause a denial of service in .NET applications due to inefficient algorithmic complexity in cryptographic components.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-84008?
CVE-2026-84008 is a high-severity denial of service vulnerability in Microsoft .NET Framework 3.5, published on 13 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Inefficient algorithmic complexity in .NET allows an unauthorized attacker to deny service over a network.
Weakness: CWE-407
Which versions are affected by CVE-2026-84008?
8 open source packages ship an affected version, including System.Security.Cryptography.Pkcs.
| Package | Affected | Fixed in |
|---|---|---|
System.Security.Cryptography.Pkcs NuGet | From 10.0.0 | 10.0.13 |
System.Security.Cryptography.Pkcs NuGet | From 10.0.0 | 10.0.13 |
System.Security.Cryptography.Pkcs NuGet | From 11.0.0-preview.1 | 11.0.0-rc.2 |
System.Security.Cryptography.Pkcs NuGet | From 11.0.0-preview.1 | 11.0.0-rc.2 |
System.Security.Cryptography.Pkcs NuGet | From 8.0.0 | 8.0.2 |
System.Security.Cryptography.Pkcs NuGet | From 8.0.0 | 8.0.2 |
2 more packages
System.Security.Cryptography.Pkcs NuGet | From 9.0.0 | 9.0.21 |
System.Security.Cryptography.Pkcs NuGet | From 9.0.0 | 9.0.21 |
How do I fix CVE-2026-84008?
Upgrade System.Security.Cryptography.Pkcs to a fixed version for your release line: 10.0.13, 11.0.0-rc.2, 8.0.2 or 9.0.21.
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-2026-84008 being exploited?
There is no known exploitation of CVE-2026-84008 in the wild and no public exploit code.
Sources
Also known as GHSA-846f-f764-76mx, MINI-77gc-3crv-8x5m, MINI-fm24-c5wp-cv9p, MINI-g76p-mfxr-ggxm, MINI-hq8w-rrjm-mp64, MINI-m38f-v26q-34j9 and 4 more.