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.
Published: 2026-09-17
Score: 9.2 Critical
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

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Tracking

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Advisories

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History

Thu, 17 Sep 2026 22:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Thu, 17 Sep 2026 19:30:00 +0000

Type Values Removed Values Added
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.
Title Improper validation of certificate with host mismatch in AWS IoT Device SDK for Python
First Time appeared Aws
Aws awsiotpythonsdk
Weaknesses CWE-297
CPEs cpe:2.3:a:aws:awsiotpythonsdk:*:*:*:*:*:*:*:*
Vendors & Products Aws
Aws awsiotpythonsdk
References
Metrics cvssV3_1

{'score': 8.1, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H'}

cvssV4_0

{'score': 9.2, 'vector': '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'}

Subscriptions

Aws Awsiotpythonsdk
cve-icon MITRE

Status: PUBLISHED

Assigner: AMZN

Published:

Updated: 2026-09-17T19:57:09.515Z

Reserved: 2026-09-17T12:43:02.381Z

Link: CVE-2026-92943

cve-icon Vulnrichment

Updated: 2026-09-17T19:57:01.778Z

cve-icon NVD

Status : Received

Published: 2026-09-17T20:18:59.333

Modified: 2026-09-17T20:18:59.333

Link: CVE-2026-92943

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses
  • CWE-297

    Improper Validation of Certificate with Host Mismatch