Detections
Analytics

Amazon Linux 2 : python3 (ALAS-2026-4025)

high Nessus Plugin ID 371782

Synopsis

The remote Amazon Linux 2 host is missing a security update.

Description

The version of python3 installed on the remote host is prior to 3.7.16-1. It is, therefore, affected by a vulnerability as referenced in the ALAS2-2026-4025 advisory.

 ssl.SSLContext.wrap_bio() didn't require the server_hostname argumentto not be None if ssl.SSLContext.check_hostname was set. Due to amissing parameter check in SSLObject, if the server_hostname argumentisn't supplied then hostname verification would be silently skipped.

 This defect could lead to programs where certificate hostname verification*appeared* to be succeeding with SSLContext.check_hostname = True and noValueError being raised due to misconfiguration.

 If the program passes a server_hostname value that isn't an empty stringor None to any of these APIs then certificate hostname verificationproceeds as expected and the program is not affected by this vulnerability.

 Mitigating this vulnerability doesn't require updating Python or applyingthe patch. To mitigate, pass a valid non-None and non-emptyserver_hostname value to SSLContext.wrap_bio(),asyncio.create_connection(), or asyncio.loop.start_tls() andcertificate hostname verification will proceed as expected. Upgrading tothe latest version of Python or applying the patch only changes thebehavior from silently skipping hostname verification to raising aValueError, similar to SSLContext.wrap_socket(), when server_hostnameisn't supplied. (CVE-2026-19553)

Tenable has extracted the preceding description block directly from the tested product security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Solution

Run 'yum update python3' or or 'yum update --advisory ALAS2-2026-4025' to update your system.

See Also

https://alas.aws.amazon.com//AL2/ALAS2-2026-4025.html

https://alas.aws.amazon.com/faqs.html

https://explore.alas.aws.amazon.com/CVE-2026-19553.html

Plugin Details

Severity: High

ID: 371782

File Name: al2_ALAS-2026-4025.nasl

Version: 1.1

Type: Local

Agent: unix

Published: 10/24/2026

Updated: 10/24/2026

Supported Sensors: Frictionless Assessment AWS, Frictionless Assessment Agent, Nessus Agent, Agentless Assessment, Continuous Assessment, Tenable Cloud Security, Tenable Self-Hosted Container Security, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 6.3

Percentile: 96.3

CVSS v2

Risk Factor: High

Base Score: 7.1

Temporal Score: 5.3

Vector: CVSS2#AV:N/AC:H/Au:N/C:C/I:C/A:N

CVSS Score Source: CVE-2026-19553

CVSS v3

Risk Factor: High

Base Score: 7.4

Temporal Score: 6.4

Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

CVSS v4

Risk Factor: High

Base Score: 7.6

Threat Score: 4.9

Threat Vector: CVSS:4.0/E:U

Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N

Vulnerability Information

CPE: cpe:/o:amazon:linux:2, p-cpe:/a:amazon:linux:python3-debug, p-cpe:/a:amazon:linux:python3-debuginfo, p-cpe:/a:amazon:linux:python3-devel, p-cpe:/a:amazon:linux:python3-libs, p-cpe:/a:amazon:linux:python3-test, p-cpe:/a:amazon:linux:python3-tkinter, p-cpe:/a:amazon:linux:python3-tools, p-cpe:/a:amazon:linux:python3

Required KB Items: Host/local_checks_enabled, Host/AmazonLinux/release, Host/AmazonLinux/rpm-list

Exploit Ease: No known exploits are available

Patch Publication Date: 10/24/2026

Vulnerability Publication Date: 8/20/2026

Reference Information

CVE: CVE-2026-19553

IAVA: 2026-A-0890