CVE-2026-19642 Out-of-bounds write in the Base64 decoder in Amazon aws-sdk-cpp

Medium 6.0 Published Updated

A remote authenticated user can trigger heap memory corruption or crashes in applications using the AWS C++ SDK via crafted Base64 input.

Exploited in the wild
Not known
Login needed
Any signed-in user
Attackable
Over the internet
Victim action needed
Not needed
Fix
Available

What is CVE-2026-19642?

CVE-2026-19642 is a medium-severity memory corruption vulnerability in aws-sdk-cpp, published on 12 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

An out-of-bounds write issue in the Base64 decoder in Amazon aws-sdk-cpp before 1.11.862 might allow a remote authenticated user to cause a crash or heap memory corruption in an application that processes crafted Base64-encoded input.

To remediate this issue, users should upgrade to version 1.11.862.

Weakness: CWE-787

Which versions are affected by CVE-2026-19642?

It affects 1 product.

Products include Amazon Aws Software Development Kit.

How do I fix CVE-2026-19642?

Upgrade to a fixed version.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2026-19642 being exploited?

There is no known exploitation of CVE-2026-19642 in the wild and no public exploit code.

Sources

Also known as GHSA-wxx3-prfc-69xx.

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