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Ubuntu 22.04 LTS / 24.04 LTS / 26.04 LTS : idna vulnerability (USN-8549-1)

medium Nessus Plugin ID 327339

Synopsis

The remote Ubuntu host is missing a security update.

Description

The remote Ubuntu 22.04 LTS / 24.04 LTS / 26.04 LTS host has a package installed that is affected by a vulnerability as referenced in the USN-8549-1 advisory.

 It was discovered that idna did not properly reject oversized inputs before performing expensive processing. An attacker could possibly use this issue to cause idna to consume significant resources, leading to a denial of service.

Tenable has extracted the preceding description block directly from the Ubuntu 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

Update the affected python3-idna package.

See Also

https://ubuntu.com/security/notices/USN-8549-1

Plugin Details

Severity: Medium

ID: 327339

File Name: ubuntu_USN-8549-1.nasl

Version: 1.1

Type: Local

Agent: unix

Published: 7/16/2026

Updated: 7/16/2026

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

Risk Information

VPR

Risk Factor: Low

Score: 1.2

Percentile: 0.01

CVSS v2

Risk Factor: Medium

Base Score: 5

Temporal Score: 3.7

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

CVSS Score Source: CVE-2026-45409

CVSS v3

Risk Factor: Medium

Base Score: 5.3

Temporal Score: 4.6

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

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

CVSS v4

Risk Factor: Medium

Base Score: 6.9

Threat Score: 2.7

Threat Vector: CVSS:4.0/E:U

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

Vulnerability Information

CPE: cpe:/o:canonical:ubuntu_linux:26.04:-:lts, cpe:/o:canonical:ubuntu_linux:22.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:python3-idna, cpe:/o:canonical:ubuntu_linux:24.04:-:lts

Required KB Items: Host/cpu, Host/Ubuntu, Host/Ubuntu/release, Host/Debian/dpkg-l

Exploit Ease: No known exploits are available

Patch Publication Date: 7/15/2026

Vulnerability Publication Date: 5/19/2026

Reference Information

CVE: CVE-2026-45409

USN: 8549-1