high7.5
CVE-2026-18140
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
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. To remediate this issue, users should upgrade to aws-smithy-json 0.62.7 or later and rebuild.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| rust | aws-smithy-json | <= 0.62.6 | 0.62.7 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Amazon | Aws-Smithy-Json | before 0.62.7 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-8ffr-xgwf-xj56
- https://github.com/smithy-lang/smithy-rs/security/advisories/GHSA-8ffr-xgwf-xj56
- https://nvd.nist.gov/vuln/detail/CVE-2026-18140
- https://github.com/smithy-lang/smithy-rs/pull/4685
- https://github.com/smithy-lang/smithy-rs/commit/8f0882046c467981ba5b4fd91a10befa96bd262f
- https://aws.amazon.com/security/security-bulletins/2026-067-aws
- https://crates.io/crates/aws-smithy-json/0.62.7
- https://aws.amazon.com/security/security-bulletins/2026-067-aws/