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

Severity: high (CVSS 8.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-06-12 · updated 2026-10-26
Weakness: CWE-415

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

aws-c-http: from 0.4.22 through 0.10.15

References

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

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