CVE-2026-22611 AWS SDK for .NET V4 adopted defense in depth enhancement for region parameter value
An attacker with environment access can manipulate region parameters to route AWS API calls to non-AWS hosts, bypassing intended security controls.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-22611?
CVE-2026-22611 is a low-severity server-side request forgery vulnerability in aws-sdk-net, published on 10 Jan 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
AWS SDK for .NET works with Amazon Web Services to help build scalable solutions with Amazon S3, Amazon DynamoDB, Amazon Glacier, and more. From versions 4.0.0 to before 4.0.3.3, Customer applications could be configured to improperly route AWS API calls to non-existent or non-AWS hosts. This notification is related to the use of specific values for the region input field when calling AWS services. An actor with access to the environment in which the SDK is used could set the region input field to an invalid value. This issue has been patched in version 4.0.3.3.
Weakness: CWE-20
Which versions are affected by CVE-2026-22611?
2 open source packages ship an affected version, including AWSSDK.Core.
| Package | Affected | Fixed in |
|---|---|---|
AWSSDK.Core NuGet | From 4.0.0 | 4.0.3.3 |
AWSSDK.Core NuGet | From 4.0.0 | 4.0.3.3 |
How do I fix CVE-2026-22611?
Upgrade AWSSDK.Core to 4.0.3.3 or later.
Upgrade, and send outbound requests through an allow-list that blocks internal addresses. More about Server-side request forgery.
Is CVE-2026-22611 being exploited?
There is no known exploitation of CVE-2026-22611 in the wild and no public exploit code.
Sources
Also known as GHSA-9cvc-h2w8-phrp.