Vulnerability · Published Jun 12, 2026 · Assigned by AMZN

CVE-2026-12043Heap double-free in AWS Common Runtime aws-c-http

High 8.8

In plain English

A high-severity double free in aws-c-http from AWS. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 28% of all known vulnerabilities).

Severity (CVSS 3.1)8.8High

Exploit odds (30 days)0.3%top 71.7% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

Improper handling of HPACK dynamic table size updates in the AWS Common Runtime aws-c-http library might allow a remote threat actor operating a server to cause memory corruption on a connecting client application, potentially leading to arbitrary code execution, via a crafted sequence of HTTP/2 HEADERS frames. To remediate this issue, users should upgrade to aws-c-http version 0.11.0.

Affected products (as reported)

Vendor	Product	Versions
AWS	aws-c-http	0.4.22 – through 0.10.15

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

References

https://github.com/awslabs/aws-c-http/releases/tag/v0.11.0 patch
https://aws.amazon.com/security/security-bulletins/2026-043-aws/ vendor-advisory
https://github.com/awslabs/aws-c-http/security/advisories/GHSA-rmjr-3qpm-vh98 third-party-advisory