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 Vector Network

Attack Complexity Low

Privileges Required None

Attack Requirements None

User Interaction None

Vulnerable System Confidentiality Impact None

Vulnerable System Integrity Impact None

Vulnerable System Availability Impact High

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
AWS aws-sdk-rust unaffected
Version Status Constraints
0 affected < release-2026-06-02

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Project Subscriptions

Vendors Products
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Aws-sdk-rust Subscribe
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://aws.amazon.com/security/security-bulletins/2026-061-aws/ cve-icon
https://github.com/awslabs/aws-sdk-rust/releases/tag/release-2026-06-02 cve-icon
https://github.com/smithy-lang/smithy-rs/security/advisories/GHSA-4f2p-7j38-4xrg cve-icon
History

Tue, 21 Jul 2026 19:45:00 +0000

Type Values Removed Values Added
Description 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.
Title Uncontrolled recursion in smithy-rs generated JSON, CBOR, and XML deserializers allows unauthenticated remote denial of service via recursive shapes
First Time appeared Aws
Aws aws-sdk-rust
Weaknesses CWE-770
CPEs cpe:2.3:a:aws:aws-sdk-rust:*:*:*:*:*:*:*:*
Vendors & Products Aws
Aws aws-sdk-rust
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

cvssV4_0

{'score': 8.7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: AMZN

Published:

Updated: 2026-07-21T19:37:44.216Z

Reserved: 2026-07-16T13:52:17.532Z

Link: CVE-2026-15957

cve-icon Vulnrichment

No data.

cve-icon NVD

No data.

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses