CVE-2026-92943 — AWS
HIGHCVE-2026-92943 is a high-severity (CVSS 8.1) Improper validation of certificate with host mismatch vulnerability. No vendor fix is recorded yet; mitigation options are listed below.
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…
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-92943.
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.
Detection & mitigation playbook
VulnerabilityDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for the affected component, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Remediation status
No patched version of the affected component has shipped for CVE-2026-92943 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-92943 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-92943. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-92943 in your dependencies?
O3 Security finds CVE-2026-92943 across dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.