CVE-2026-18140

HIGH8.7

Uncontrolled recursion in the aws-smithy-json unknown-key skip path allows unauthenticated remote denial of service in smithy-rs generated servers

Published Jul 30, 2026

Modified 2 weeks ago

Details

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.

To remediate this issue, users should upgrade to aws-smithy-json 0.62.7 or later and rebuild.

References

ADVISORY

https://aws.amazon.com/security/security-bulletins/2026-067-aws/

FIX

https://crates.io/crates/aws-smithy-json/0.62.7

ADVISORY

https://github.com/smithy-lang/smithy-rs/security/advisories/GHSA-8ffr-xgwf-xj56

ADVISORY

https://www.cve.org/CVERecord?id=CVE-2026-18140

CVSS Analysis

CVSS v4.0