---
cve: "CVE-2026-18140"
severity: "HIGH"
cvss: 8.7
epss: "0.4%"
vendor: "aws"
kev: false
exploited: false
published: "2026-07-30 18:34:04"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-20T20:06:29+02:00"
---

# CVE-2026-18140

> 8.7 HIGH · 🧪 PoC

## Beschreibung

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.

## CVSS-Vektor

```
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
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |

## Referenzen

- <https://crates.io/crates/aws-smithy-json/0.62.7>
- <https://aws.amazon.com/security/security-bulletins/2026-067-aws/>
- <https://github.com/smithy-lang/smithy-rs/security/advisories/GHSA-8ffr-xgwf-xj56>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-18140) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_