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

8.7HIGH

Key Information:

Vendor

Aws

Status
Aws-c-http
Vendor
CVE Published:
12 June 2026

What is CVE-2026-12043?

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 Version(s)

aws-c-http 0.4.22 <= 0.10.15

References

https://github.com/awslabs/aws-c-http/releases/tag/v0.11.0
patch
https://aws.amazon.com/security/security-bulletins/2026-0...
vendor-advisory
https://github.com/awslabs/aws-c-http/security/advisories...
third-party-advisory

CVSS V4

Score:
8.7
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
Unknown

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.