Ubuntu 22.04 LTS / 24.04 LTS / 25.10 : .NET vulnerabilities (USN-8176-1)

high Nessus Plugin ID 306722

Synopsis

The remote Ubuntu host is missing one or more security updates.

Description

The remote Ubuntu 22.04 LTS / 24.04 LTS / 25.10 host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-8176-1 advisory.

Ludvig Pedersen discovered that the System.Security.Cryptography.Xml library in .NET incorrectly handled certain XML inputs. An attacker could possibly use this issue to consume excessive resources, resulting in a denial of service. (CVE-2026-33116, CVE-2026-26171)

Ludvig Pedersen and Kevin Jones discovered that the System.Security.Cryptography.Xml library in .NET incorrectly handled certain XML inputs. An attacker could possibly use this issue to cause .NET to crash, resulting in a denial of service. (CVE-2026-32203)

Ludvig Pedersen discovered that the System.Net.Mail component in .NET incorrectly handled certain inputs.
An attacker could possibly use this issue to perform a network spoofing attack. (CVE-2026-32178)

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

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

Solution

Update the affected packages.

See Also

https://ubuntu.com/security/notices/USN-8176-1

Plugin Details

Severity: High

ID: 306722

File Name: ubuntu_USN-8176-1.nasl

Version: 1.3

Type: Local

Agent: unix

Published: 4/16/2026

Updated: 5/8/2026

Supported Sensors: Agentless Assessment, Continuous Assessment, Frictionless Assessment Agent, Frictionless Assessment AWS, Frictionless Assessment Azure, Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Low

Score: 3.6

CVSS v2

Risk Factor: High

Base Score: 7.8

Temporal Score: 5.8

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

CVSS Score Source: CVE-2026-32178

CVSS v3

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.5

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

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

CVSS Score Source: CVE-2026-33116

Vulnerability Information

CPE: p-cpe:/a:canonical:ubuntu_linux:dotnet-sdk-8.0-source-built-artifacts, cpe:/o:canonical:ubuntu_linux:24.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:dotnet-host-8.0, p-cpe:/a:canonical:ubuntu_linux:dotnet-host-9.0, p-cpe:/a:canonical:ubuntu_linux:dotnet-sdk-10.0, p-cpe:/a:canonical:ubuntu_linux:aspnetcore-targeting-pack-9.0, p-cpe:/a:canonical:ubuntu_linux:dotnet9, p-cpe:/a:canonical:ubuntu_linux:dotnet-runtime-10.0, p-cpe:/a:canonical:ubuntu_linux:dotnet-sdk-dbg-10.0, cpe:/o:canonical:ubuntu_linux:25.10, p-cpe:/a:canonical:ubuntu_linux:aspnetcore-runtime-9.0, p-cpe:/a:canonical:ubuntu_linux:dotnet-sdk-8.0, p-cpe:/a:canonical:ubuntu_linux:aspnetcore-runtime-10.0, p-cpe:/a:canonical:ubuntu_linux:dotnet-host-10.0, p-cpe:/a:canonical:ubuntu_linux:dotnet-runtime-dbg-9.0, p-cpe:/a:canonical:ubuntu_linux:dotnet-sdk-aot-10.0, p-cpe:/a:canonical:ubuntu_linux:dotnet-targeting-pack-8.0, p-cpe:/a:canonical:ubuntu_linux:dotnet-runtime-dbg-8.0, p-cpe:/a:canonical:ubuntu_linux:aspnetcore-targeting-pack-10.0, p-cpe:/a:canonical:ubuntu_linux:dotnet-apphost-pack-10.0, p-cpe:/a:canonical:ubuntu_linux:dotnet-apphost-pack-9.0, p-cpe:/a:canonical:ubuntu_linux:aspnetcore-runtime-8.0, p-cpe:/a:canonical:ubuntu_linux:aspnetcore-targeting-pack-8.0, p-cpe:/a:canonical:ubuntu_linux:dotnet10, p-cpe:/a:canonical:ubuntu_linux:dotnet-sdk-aot-9.0, p-cpe:/a:canonical:ubuntu_linux:dotnet-apphost-pack-8.0, p-cpe:/a:canonical:ubuntu_linux:dotnet-runtime-8.0, p-cpe:/a:canonical:ubuntu_linux:dotnet8, p-cpe:/a:canonical:ubuntu_linux:netstandard-targeting-pack-2.1-8.0, p-cpe:/a:canonical:ubuntu_linux:aspnetcore-runtime-dbg-9.0, p-cpe:/a:canonical:ubuntu_linux:dotnet-sdk-dbg-8.0, p-cpe:/a:canonical:ubuntu_linux:dotnet-sdk-9.0-source-built-artifacts, p-cpe:/a:canonical:ubuntu_linux:netstandard-targeting-pack-2.1-9.0, p-cpe:/a:canonical:ubuntu_linux:dotnet-hostfxr-8.0, p-cpe:/a:canonical:ubuntu_linux:dotnet-targeting-pack-9.0, p-cpe:/a:canonical:ubuntu_linux:dotnet-templates-9.0, p-cpe:/a:canonical:ubuntu_linux:dotnet-runtime-dbg-10.0, p-cpe:/a:canonical:ubuntu_linux:dotnet-sdk-10.0-source-built-artifacts, p-cpe:/a:canonical:ubuntu_linux:dotnet-templates-8.0, p-cpe:/a:canonical:ubuntu_linux:dotnet-sdk-9.0, p-cpe:/a:canonical:ubuntu_linux:dotnet-hostfxr-10.0, p-cpe:/a:canonical:ubuntu_linux:dotnet-runtime-9.0, p-cpe:/a:canonical:ubuntu_linux:dotnet-targeting-pack-10.0, p-cpe:/a:canonical:ubuntu_linux:dotnet-sdk-dbg-9.0, p-cpe:/a:canonical:ubuntu_linux:aspnetcore-runtime-dbg-10.0, cpe:/o:canonical:ubuntu_linux:22.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:dotnet-templates-10.0, p-cpe:/a:canonical:ubuntu_linux:aspnetcore-runtime-dbg-8.0, p-cpe:/a:canonical:ubuntu_linux:dotnet-hostfxr-9.0

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

Exploit Ease: No known exploits are available

Patch Publication Date: 4/15/2026

Vulnerability Publication Date: 4/14/2026

Reference Information

CVE: CVE-2026-26171, CVE-2026-32178, CVE-2026-32203, CVE-2026-33116

IAVA: 2026-A-0339

USN: 8176-1