Ubuntu 18.04 LTS / 20.04 LTS : Linux kernel (Raspberry Pi) vulnerabilities (USN-8391-1)

high Nessus Plugin ID 318843

Synopsis

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

Description

The remote Ubuntu 18.04 LTS / 20.04 LTS host has a package installed that is affected by multiple vulnerabilities as referenced in the USN-8391-1 advisory.

It was discovered that the Linux kernel algif_aead module did not properly handle in-place cryptographic operations. This flaw is known as Copy Fail. A local attacker could use this to escalate privileges, or possibly escape a container. (CVE-2026-31431)

It was discovered that the Linux kernel did not properly handle shared page fragments during socket buffer operations, collectively known as Dirty Frag. A logic flaw existed in the XFRM ESP-in-TCP subsystem and in the RxRPC networking subsystem when processing paged fragments. A local attacker could use this to escalate privileges, or possibly escape a container. (CVE-2026-43284, CVE-2026-43500)

Several security issues were discovered in the Linux kernel. An attacker could possibly use these to compromise the system. This update corrects flaws in the following subsystems:

- Cryptographic API;

- Network drivers;

- NVME drivers;

- IPv4 networking;

- Packet sockets;

- RDS protocol;

- TLS protocol; (CVE-2024-50304, CVE-2026-23112, CVE-2026-23209, CVE-2026-31504, CVE-2026-31533, CVE-2026-43033, CVE-2026-43077, CVE-2026-43078, CVE-2026-43494, CVE-2026-46028)

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 kernel package.

See Also

https://ubuntu.com/security/notices/USN-8391-1

Plugin Details

Severity: High

ID: 318843

File Name: ubuntu_USN-8391-1.nasl

Version: 1.1

Type: Local

Agent: unix

Published: 6/5/2026

Updated: 6/5/2026

Supported Sensors: Continuous Assessment, Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Critical

Score: 10.0

CVSS v2

Risk Factor: Critical

Base Score: 10

Temporal Score: 8.7

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

CVSS Score Source: CVE-2026-23112

CVSS v3

Risk Factor: Critical

Base Score: 9.8

Temporal Score: 9.4

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

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

CVSS v4

Risk Factor: High

Base Score: 8.6

Threat Score: 8.6

Threat Vector: CVSS:4.0/E:A

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

CVSS Score Source: CVE-2026-31431

Vulnerability Information

CPE: cpe:/o:canonical:ubuntu_linux:18.04:-:lts, cpe:/o:canonical:ubuntu_linux:20.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-1143-raspi

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

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 6/4/2026

Vulnerability Publication Date: 4/9/2024

CISA Known Exploited Vulnerability Due Dates: 5/15/2026

Reference Information

CVE: CVE-2024-50304, CVE-2026-23112, CVE-2026-23209, CVE-2026-31431, CVE-2026-31504, CVE-2026-31533, CVE-2026-43033, CVE-2026-43077, CVE-2026-43078, CVE-2026-43284, CVE-2026-43494, CVE-2026-43500, CVE-2026-46028

USN: 8391-1