Smithy-RS is a Rust code generation and runtime framework that generates HTTP clients and servers from Smithy interface definitions, powering the AWS SDK for Rust and custom service implementations. Uncontrolled recursion in the JSON, CBOR, and XML deserializer functions emitted by Amazon smithy-rs code generation could allow remote attackers to cause a denial of service (process abort via stack exhaustion) via a small request containing deeply nested data for a recursive model shape to a generated SDK or server. To mitigate this issue, users should upgrade to aws-sdk-rust release-2026-06-02 or later.
Users building custom servers with smithy-rs codegen should regenerate from smithy-rs release-2026-06-01 or later.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Attack Requirements
None
No additional conditions
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
None
No data leak
Integrity
None
No data modification
Availability
High
Complete denial of service
CVSS Vector v4.0
Weakness Type (CWE)
References 3
https://aws.amazon.com/security/security-bulletins/2026-061-aws/
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https://github.com/awslabs/aws-sdk-rust/releases/tag/release-2026-06-02
ff89ba41-3aa1-4d27-914a-91399e9639e5
https://github.com/smithy-lang/smithy-rs/security/advisories/GHSA-4f2p-7j38-4xrg
ff89ba41-3aa1-4d27-914a-91399e9639e5