Low, CVSS 3.7NuGetPublished
AWS SDK for .NET V4 adopted defense in depth enhancement for region parameter value
CVE-2026-22611 · GHSA-9cvc-h2w8-phrp
- Affected
- NuGet awssdk.core >= 4.0.0, < 4.0.3.3
- Fixed in
- 4.0.3.3· Vendor fix available
- Issue
- 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. A defense-in-depth enhancement has been implemented in the AWS SDK for .NET v4. This enhancement validates that a region used to construct an endpoint URL is a valid host label. The change was released on Nov 21, 2025. This advisory is informational to help customers understand their responsibilities regarding configuration security. Impact Customer applications could be configured to improperly route AWS API calls to non-existent or non-AWS hosts. While the SDK was functioning safely within the requirements of the shared responsibility model, additional safeguards have been added to support secure customer implementations. Impacted versions: All versions of the AWS SDK for .NET V4 prior to the 4.0.139.0 release (the AWS SDK for .NET V3 was not…
Recommended action: Upgrade to 4.0.3.3 or later, then redeploy and verify.A vendor fix does not resolve your finding until you verify it in your own systems.