---
id: "GHSA-hhhc-wq73-w43x"
kind: "vulnerability"
aliases: ["GHSA-hhhc-wq73-w43x"]
title: "CVE-2026-105811 - Authorization bypass through a user-controlled key in the Amazon Q Business Lambda hook sample in QnABot on AWS"
severity: "high"
cvss: null
epss: null
exploited: false
status: "open"
category: "vendor"
products: []
ecosystems: []
tags: ["aws", "lab-disclosure", "q-business", "qnabot", "s3", "self-hosted", "vendor"]
not_affected_if: ["hook-sample-not-deployed", "qnabot-7.4.6-or-later"]
published_at: null
first_seen_at: "2026-10-24T18:56:55+00:00"
updated_at: "2026-10-25T04:51:37+00:00"
sources: [{"source": "lab", "url": "https://aws.amazon.com/security/security-bulletins/rss/2026-126-aws/", "first_seen_at": "2026-10-24T18:56:55+00:00"}]
---

# CVE-2026-105811 - Authorization bypass through a user-controlled key in the Amazon Q Business Lambda hook sample in QnABot on AWS

The optional Amazon Q Business Lambda hook sample in QnABot on AWS versions 7.0.0 through 7.4.5 has an authorization bypass through a user-controlled key. An authenticated remote user can read arbitrary Amazon S3 objects in the AWS account where it is deployed.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check whether the Amazon Q Business Lambda hook sample stack (q-business-lambda-hook) is deployed in your AWS account, separately from the QnABot stack.
- Check the deployed QnABot on AWS version; versions `7.0.0` through `7.4.5` are affected.

## Fix

- Update the QnABot on AWS stack to `7.4.6` or later.
- Redeploy the Amazon Q Business Lambda hook sample stack after the update; updating QnABot alone does not deliver the fix.
- Patch any forked or derivative code with the same changes.

## Timeline

- 2026-10-24T18:56:55+00:00 lab https://aws.amazon.com/security/security-bulletins/rss/2026-126-aws/ — AWS: CVE-2026-105811 - Authorization bypass through a user-controlled key in the Amazon Q Business Lambda hook sample in QnABot on AWS

## Documents

- [advisory] AWS: CVE-2026-105811 - Authorization bypass through a user-controlled key in the Amazon Q Business Lambda hook sample in QnABot on AWS https://aws.amazon.com/security/security-bulletins/rss/2026-126-aws/

## From the sources

CVE-2026-105811 - Authorization bypass through a user-controlled key in the Amazon Q Business Lambda hook sample in QnABot on AWS

### CVE-2026-105811 - Authorization bypass through a user-controlled key in the Amazon Q Business Lambda hook sample in QnABot on AWS

Bulletin ID: 2026-126-AWS Scope: AWS Content Type: Important (requires attention) Publication Date: 10/06/2026 13:00 PM PDT

Description:

QnABot on AWS is a sample solution of a multi-channel, multi-language conversational interface (chatbot) that responds to your customer's questions, answers, and feedback. We identified CVE-2026-105811 in the optional Amazon Q Business Lambda hook sample of QnABot on AWS. The Amazon Q Business Lambda hook sample (q-business-lambda-hook) is an optional integration sample included in the QnABot on AWS repository. It requires separate, manual deployment and additional setup; it is not deployed automatically with QnABot. Customers who have not deployed this sample are not affected and do not need to take action.

Authorization bypass through a user-controlled key in the sample included with QnABot on AWS versions 7.0.0 through 7.4.5 might allow an authenticated remote user to read arbitrary Amazon S3 objects in the deploying AWS account.

To remediate this issue, affected customers should update the QnABot on AWS stack to version 7.4.6 or later and then redeploy the Amazon Q Business Lambda hook sample stack. Updating the QnABot on AWS stack alone does not deliver the fix.

Impacted versions: >=7.0.0, <7.4.6

Resolution:

This issue has been addressed in QnABot on AWS version v7.4.6. We recommend upgrading to the latest version and ensuring any forked or derivative code is patched to incorporate the new fixes. Customers should update the QnABot on AWS stack to version 7.4.6 or later and then redeploy the Amazon Q Business Lambda hook sample stack. Updating the QnABot on AWS stack alone does not deliver the fix. No action is required for customers who do not currently use the Amazon Q Business Lambda hook sample stack.

Workarounds:

There is no workaround available.

References:

- CVE-2026-105811
- GHSA-hhhc-wq73-w43x

Acknowledgement:

We would like to thank Oren Yomtov for collaborating on this issue through the coordinated vulnerability disclosure process.

 Please email aws-security@amazon.com with any security questions or concerns.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_