Quick answers
- Is CVE-2026-12043 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-12043 being exploited in the wild.
- How severe is CVE-2026-12043?
- High severity, with a CVSS score of 8.8, published 12 June 2026.
- Which products and versions are affected?
- Amazon Web Services Aws-C-Http <unknown>, >= 0.4.22, <= 0.10.15; Amazon Web Services SDK for Java v2 >= 2.44.27, <= 2.44.14.
- Is there a fix for CVE-2026-12043?
- No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- How is CVE-2026-12043 attacked?
- It is attacked over the network.
- Am I affected by CVE-2026-12043?
- Check whether you run Amazon AWS, Amazon Web Services Aws-C-Http or Amazon Web Services SDK for Java v2 at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
A heap double-free vulnerability exists in the aws-c-http library within AWS Common Runtime. The root cause is improper memory management where a heap-allocated object is freed multiple times, potentially triggered through malformed HTTP requests or specific protocol handling paths. The vulnerability can be exploited to corrupt heap metadata, bypass ASLR/other mitigations, or achieve arbitrary code execution. Attack preconditions depend on whether the library is exposed to untrusted network input; if used in a server context, remote exploitation is possible without authentication. AWS has published security guidance; patches are expected to be available through aws-c-http library updates and AWS SDK upgrades.
Affected products
- AWS aws-c-http <unknown>
Timeline
- 2026-09-22: disclosed