# CVE-2026-92943: Improper validation of certificate with host mismatch in AWS IoT Device SDK for Python

> An attacker can impersonate AWS IoT endpoints to read telemetry and inject messages due to improper TLS certificate host validation in the Python SDK.

- **Severity:** Critical 9.2 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 17 Sep 2026
- **Updated:** 17 Sep 2026
- **Also known as:** GHSA-g7vp-3rxx-v25r

## What is CVE-2026-92943?

CVE-2026-92943 is a critical vulnerability in AWSIoTPythonSDK, published on 17 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Improper validation of certificate with host mismatch in the MQTT client TLS connection layer in AWS IoT Device SDK for Python 1.5.3 through 1.6.0 on Python 3.7 and later might allow an adversary-in-the-middle actor to impersonate the AWS IoT Core endpoint, read device telemetry, and inject arbitrary MQTT messages that the device processes as authentic, via a certificate issued for an unrelated hostname by a certificate authority present in the device trust store.

To remediate this issue, users should upgrade to version 1.6.1.

Weakness: CWE-297 (Improper Validation of Certificate with Host Mismatch)

## Which versions are affected by CVE-2026-92943?


## How do I fix CVE-2026-92943?

No fix has been published for CVE-2026-92943 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-92943 being exploited?

There is no known exploitation of CVE-2026-92943 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-92943 and fix it if it is affected.

What it is: CVE-2026-92943 is a critical vulnerability in AWSIoTPythonSDK, published on 17 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-92943 in the wild and no public exploit code.

Affected product: AWSIoTPythonSDK. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-92943/ (Markdown: https://insights.sbomify.com/CVE-2026-92943/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-92943
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-92943
- OSV: https://osv.dev/vulnerability/CVE-2026-92943

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-92943/
Summaries are generated and may contain mistakes; the official description above is the record.