Summary
AWS Bedrock AgentCore: Improper neutralization of argument delimiters in the Python SDK install_packages()
The AWS Bedrock AgentCore Python SDK (bedrock-agentcore) provides tools for building AI agents, including a Code Interpreter client that installs Python packages into a managed sandbox. An issue exists where, under certain circumstances, improper neutralization of argument delimiters in the install_packages() method allows a remote authenticated user to execute arbitrary commands within the Code Interpreter sandbox via crafted package name arguments.
Impacted Versions
< 1.18.1
Workarounds
If you are not able to upgrade, do not pass untrusted or model-generated input to install_packages(). Applications that must accept dynamic package names should validate them against strict PyPI naming rules -- including constraining any extras group to comma-separated identifiers -- before calling the SDK.
References
If you have any questions or comments about this advisory, AWS asks that you contact AWS Security via the vulnerability reporting page or directly via email to [email protected]. Please do not create a public GitHub issue.
Acknowledgement
AWS would like to thank Sergio Garcia (@MrCloudSec) for collaborating on this issue through the coordinated issue disclosure process.
Impact
Insufficient input validation in install_packages() allows specially crafted package specifiers to bypass validation and achieve arbitrary command execution within the sandbox. A remote authenticated user who can influence the arguments to install_packages() can execute arbitrary commands within the Code Interpreter sandbox environment.
CVE-2026-16796 has a CVSS score of 7.3 (High). The vector is network-reachable, low privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (1.18.1); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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See it in your environmentNew to Kodem? Get a demo →Remediation advice
This issue has been addressed in bedrock-agentcore version 1.18.1. We recommend upgrading to the latest version and ensuring any forked or derivative code is patched to incorporate the new fixes.
Frequently Asked Questions
- What is CVE-2026-16796? CVE-2026-16796 is a high-severity security vulnerability in bedrock-agentcore (pip), affecting versions < 1.18.1. It is fixed in 1.18.1.
- How severe is CVE-2026-16796? CVE-2026-16796 has a CVSS score of 7.3 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of bedrock-agentcore are affected by CVE-2026-16796? bedrock-agentcore (pip) versions < 1.18.1 is affected.
- Is there a fix for CVE-2026-16796? Yes. CVE-2026-16796 is fixed in 1.18.1. Upgrade to this version or later.
- Is CVE-2026-16796 exploitable, and should I be worried? Whether CVE-2026-16796 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-16796 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-16796? Upgrade
bedrock-agentcoreto 1.18.1 or later.