GitHub Advisoryadvisory · crates.io
GHSA-8ffr-xgwf-xj56 aws-smithy-json: Uncontrolled recursion in the aws-smithy-json unknown-key skip path allows unauthenticated remote denial of service in smithy-rs generated servers
HIGH
Official page ↗
- Aliases
- CVE-2026-18140
- Ecosystem
- crates.io
- Packages
- aws-smithy-json
- Severity
- High
- CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Weaknesses
- CWE-674
- Reviewed
- 2026-10-02
Affected packages
• crates.io aws-smithy-json: < 0.62.7 → fixed in 0.62.7
Description
Summary
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. An issue exists which allows uncontrolled recursion in the unknown-key skip path of the Amazon aws-smithy-json runtime crate in versions 0.62.6 and earlier.
Impact
Uncontrolled recursion in the unknown-key skip path of the aws-smithy-json runtime crate before 0.62.7, which the smithy-rs code generator invokes from every generated struct deserializer, might allow remote unauthenticated users to cause a denial of service (process abort via stack exhaustion) via a single small HTTP request containing deeply nested JSON to a smithy-rs generated server.
Impacted versions: aws-smithy-json <= 0.62.6
Patches
This issue has been addressed in aws-smithy-json version 0.62.7. We recommend upgrading to the latest version and ensuring any forked or derivative code is patched to incorporate the new fixes.
Workarounds
There are no workarounds besides updating to the patched version.
References
If you have any questions or comments about this advisory, AWS asks that you contact [AWS/Amazon] Security via their vulnerability reporting page or directly via email to [email protected]. Please do not create a public GitHub issue.
Related
Alias · CVE (1)
- CVE-2026-18140 Uncontrolled recursion in the unknown-key skip path of the aws-smithy-json runtime crate before 0.62.7, which the smithy-rs code generator… vulnerability
Weakness · CWE (1)
- CWE-674 Uncontrolled Recursion weakness
References
- https://github.com/smithy-lang/smithy-rs/security/advisories/GHSA-8ffr-xgwf-xj56 web
- https://nvd.nist.gov/vuln/detail/CVE-2026-18140 advisory
- https://github.com/smithy-lang/smithy-rs/pull/4685 web
- https://github.com/smithy-lang/smithy-rs/commit/8f0882046c467981ba5b4fd91a10befa96bd262f web
- https://aws.amazon.com/security/security-bulletins/2026-067-aws web
- https://crates.io/crates/aws-smithy-json/0.62.7 web
- https://github.com/smithy-lang/smithy-rs package