CVE-2026-16796: AWS Bedrock AgentCore Improper Neutralization Of Argument Delimiters Vulnerability

HIGH
Advisory Identifier: GHSA-j6g5-3hh3-pgw8
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CVSS 7.3
CWE-88
Published
Advisory Summary

CVE-2026-16796 is a HIGH (CVSS 7.3) improper neutralization of argument delimiters vulnerability (CWE-88: Improper Neutralization of Argument Delimiters in a Command ('Argument Injection')) affecting AWS Bedrock AgentCore libraries in the PyPI ecosystem. The issue involves improper neutralization of argument delimiters in the python sdk install_packages(). Remediation is available by upgrading affected packages to version 1.18.1.

CVE-2026-16796 at a Glance

CVE Identifier CVE-2026-16796
GHSA Identifier GHSA-j6g5-3hh3-pgw8
Severity HIGH
CVSS v3.1 Base Score 7.3
CWE Classification CWE-88: Improper Neutralization of Argument Delimiters in a Command ('Argument Injection')
Affected Product AWS Bedrock AgentCore
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 7.3

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required Low (PR:L)
User Interaction Required (UI:R)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity High (I:H)
Availability None (A:N)

How to Fix CVE-2026-16796

To remediate this vulnerability, upgrade all affected AWS Bedrock AgentCore dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

bedrock-agentcore fixed: 1.18.1 
pip install bedrock-agentcore>=1.18.1
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

pip show bedrock-agentcore

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2026-16796, inspect your installed packages using pip:

pip show bedrock-agentcore

Analyze the terminal output to locate any version of AWS Bedrock AgentCore in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.18.1), your application is affected.

Note: The pip show bedrock-agentcore command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-88: Improper Neutralization of Argument Delimiters in a Command ('Argument Injection'), where the product constructs a string for a command to be executed by a separate component in another control sphere, but it does not properly delimit the intended arguments, options, or switches within that command string. In AWS Bedrock AgentCore, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### Summary 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. ### 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. ### Impacted Versions < 1.18.1 ### Patches 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. ### 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](https://aws.amazon.com/security/vulnerability-reporting) or directly via email to [aws-security@amazon.com](mailto:aws-security@amazon.com). 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.

CVE-2026-16796 Affected AWS Bedrock AgentCore Versions

1 component(s)
Fixed Versions:
1.18.1
Product / Package Ecosystem Affected Versions Fixed Version
bedrock-agentcore
pypi/bedrock-agentcore
PyPI
< 1.18.1
1.18.1

References

GitHub Advisory / Wiki ADVISORY
https://github.com/aws/bedrock-agentcore-sdk-python/security/advisories/GHSA-j6g5-3hh3-pgw8
NVD — CVE-2026-16796 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-16796
AWS Bedrock AgentCore Source Repository REPOSITORY
https://github.com/aws/bedrock-agentcore-sdk-python/pull/581
Security Fix Commit FIX COMMIT
https://github.com/aws/bedrock-agentcore-sdk-python/commit/3c4b4ee6b8730e6313a82c743ac37dbcc1c21cdb
AWS Bedrock AgentCore Security Information SECURITY
https://aws.amazon.com/security/security-bulletins/2026-065-aws
AWS Bedrock AgentCore Source Repository REPOSITORY
https://github.com/aws/bedrock-agentcore-sdk-python
pypi.org/project/bedrock-age... WEB
https://pypi.org/project/bedrock-agentcore/1.18.1

Frequently Asked Questions

What is CVE-2026-16796?
CVE-2026-16796 is a security vulnerability in AWS Bedrock AgentCore involving Improper neutralization of argument delimiters in the Python SDK install_packages() under CWE-88: Improper Neutralization of Argument Delimiters in a Command ('Argument Injection').
Which AWS Bedrock AgentCore versions are affected?
Affected versions include releases prior to 1.18.1 across affected packages: bedrock-agentcore.
What version fixes CVE-2026-16796?
Upgrading to 1.18.1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is bedrock-agentcore affected?
Yes, bedrock-agentcore is affected in releases prior to 1.18.1. Upgrade your dependency to 1.18.1 or later.
What is the CVSS score of CVE-2026-16796?
CVE-2026-16796 has a CVSS v3.1 base score of 7.3 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N.
What CWE is associated with CVE-2026-16796?
CVE-2026-16796 is classified under CWE-88: Improper Neutralization of Argument Delimiters in a Command ('Argument Injection') (The product constructs a string for a command to be executed by a separate component in another control sphere, but it does not properly delimit the intended arguments, options, or switches within that command string.).
How can I check PyPI dependencies for CVE-2026-16796?
Run the dependency tree command: 'pip show bedrock-agentcore'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-j6g5-3hh3-pgw8",
  "modified" : "2026-07-24T22:38:56Z",
  "published" : "2026-07-24T22:38:56Z",
  "aliases" : [ "CVE-2026-16796" ],
  "summary" : "AWS Bedrock AgentCore: Improper neutralization of argument delimiters in the Python SDK install_packages()",
  "details" : "### Summary\n\nThe 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.\n\n### Impact\nInsufficient 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.\n\n### Impacted Versions\n< 1.18.1\n\n### Patches\nThis 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.\n\n### Workarounds\nIf 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.\n\n### References\nIf you have any questions or comments about this advisory, AWS asks that you contact AWS Security via the [vulnerability reporting page](https://aws.amazon.com/security/vulnerability-reporting) or directly via email to [aws-security@amazon.com](mailto:aws-security@amazon.com). Please do not create a public GitHub issue.\n\n### Acknowledgement\n\nAWS would like to thank Sergio Garcia (@MrCloudSec) for collaborating on this issue through the coordinated issue disclosure process.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "bedrock-agentcore"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.18.1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/aws/bedrock-agentcore-sdk-python/security/advisories/GHSA-j6g5-3hh3-pgw8"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-16796"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/aws/bedrock-agentcore-sdk-python/pull/581"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/aws/bedrock-agentcore-sdk-python/commit/3c4b4ee6b8730e6313a82c743ac37dbcc1c21cdb"
  }, {
    "type" : "WEB",
    "url" : "https://aws.amazon.com/security/security-bulletins/2026-065-aws"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/aws/bedrock-agentcore-sdk-python"
  }, {
    "type" : "WEB",
    "url" : "https://pypi.org/project/bedrock-agentcore/1.18.1"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-88" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-07-24T22:38:56Z",
    "nvd_published_at" : "2026-07-23T21:17:03Z"
  }
}