CVE-2026-15957 Denial of service in aws-sdk-rust
Remote attackers can cause denial of service via stack exhaustion in smithy-rs generated deserializers by sending deeply nested data.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-15957?
CVE-2026-15957 is a high-severity denial of service vulnerability in aws-sdk-rust, published on 21 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Weakness: CWE-674
Which versions are affected by CVE-2026-15957?
How do I fix CVE-2026-15957?
No fix has been published for CVE-2026-15957 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-15957 being exploited?
There is no known exploitation of CVE-2026-15957 in the wild and no public exploit code.
Sources
Also known as GHSA-4f2p-7j38-4xrg.