Vulnerability · Published Oct 30, 2026 · Assigned by AMZN

CVE-2026-119116Use-after-free in the SetClient command handler of kmstool-enclave in AWS aws-nitro-enclaves-sdk-c

High 7.8

In plain English

A high-severity use-after-free in kmstool-enclave from AWS. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 5% of all known vulnerabilities).

Severity (CVSS 3.1)7.8High

Exploit odds (30 days)0.2%top 94.7% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

A use-after-free and double-free issue in the SetClient command handler of the kmstool-enclave sample application of AWS aws-nitro-enclaves-sdk-c before 0.4.6 may allow an application that runs on the parent EC2 instance to corrupt heap memory inside a Nitro Enclave which may lead to arbitrary code execution within the enclave. To remediate this issue, users should rebuild any enclave image that includes kmstool-enclave, or code derived from it, against aws-nitro-enclaves-sdk-c 0.4.6.

Affected products (as reported)

Vendor	Product	Versions
AWS	kmstool-enclave	0 – before 0.4.6

Weakness: CWE-416, CWE-415 · Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H

References

https://github.com/aws/aws-nitro-enclaves-sdk-c/releases/tag/v0.4.6 release-notes, patch
https://aws.amazon.com/security/security-bulletins/2026-157-aws/ vendor-advisory
https://github.com/aws/aws-nitro-enclaves-sdk-c/security/advisories/GHSA-cfhm-qfw4-j7qq third-party-advisory