Amazon Linux 2023 : bpftool6.18, kernel6.18, kernel6.18-devel (ALAS2023-2026-1649)

high Nessus Plugin ID 312149

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Synopsis

The remote Amazon Linux 2023 host is missing a security update.

Description

It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2023-2026-1649 advisory.

In the Linux kernel, the following vulnerability has been resolved:crypto: algif_aead - Revert to operating out-of-place

To mitigate this issue, we recommend that customers disable loading of the algif_aead module by running the following commands as an administrator user:

echo install algif_aead /bin/false > /etc/modprobe.d/disable-algif.conf

rmmod algif_aead

Some Amazon Linux 2 systems on the ARM64 architecture may fail the above rmmod command as they have the algif_aead module built-in. In this case, the following command and a reboot will mitigate the issue:

sudo grubby --update-kernel ALL --args initcall_blacklist=algif_aead_init (CVE-2026-31431)

In the Linux kernel, the following vulnerability has been resolved:

crypto: af_alg - limit RX SG extraction by receive buffer budget (CVE-2026-31677)

In the Linux kernel, the following vulnerability has been resolved:

crypto: authencesn - Do not place hiseq at end of dst for out-of-place decryption (CVE-2026-43033)

In the Linux kernel, the following vulnerability has been resolved:

crypto: af-alg - fix NULL pointer dereference in scatterwalk (CVE-2026-43043)

In the Linux kernel, the following vulnerability has been resolved:

crypto: algif_aead - Fix minimum RX size check for decryption (CVE-2026-43077)

In the Linux kernel, the following vulnerability has been resolved:

crypto: af_alg - Fix page reassignment overflow in af_alg_pull_tsgl (CVE-2026-43078)

Tenable has extracted the preceding description block directly from the tested product 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

Run 'dnf update kernel6.18 --releasever 2023.11.20260505' or or 'dnf update --advisory ALAS2023-2026-1649 --releasever 2023.11.20260505' to update your system.

Plugin Details

Severity: High

ID: 312149

File Name: al2023_ALAS2023-2026-1649.nasl

Version: 1.6

Type: Local

Agent: unix

Family: Amazon Linux Local Security Checks

Published: 5/5/2026

Updated: 5/20/2026

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

Risk Information

VPR

Risk Factor: Critical

Score: 9.5

CVSS v2

Risk Factor: Medium

Base Score: 4.6

Temporal Score: 4

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

CVSS Score Source: CVE-2026-43043

CVSS v3

Risk Factor: Medium

Base Score: 5.5

Temporal Score: 5.3

Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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: p-cpe:/a:amazon:linux:kernel6.18-headers, p-cpe:/a:amazon:linux:kernel6.18-modules-extra-common, p-cpe:/a:amazon:linux:kernel6.18-tools-devel, p-cpe:/a:amazon:linux:bpftool6.18-debuginfo, p-cpe:/a:amazon:linux:kernel6.18-debuginfo-common-aarch64, p-cpe:/a:amazon:linux:python3-perf6.18-debuginfo, p-cpe:/a:amazon:linux:kernel6.18, p-cpe:/a:amazon:linux:kernel6.18-tools-debuginfo, p-cpe:/a:amazon:linux:perf6.18, p-cpe:/a:amazon:linux:perf6.18-debuginfo, p-cpe:/a:amazon:linux:kernel-livepatch-6.18.20-41.237, p-cpe:/a:amazon:linux:kernel6.18-modules-extra, p-cpe:/a:amazon:linux:kernel6.18-tools, p-cpe:/a:amazon:linux:kernel6.18-devel, cpe:/o:amazon:linux:2023, p-cpe:/a:amazon:linux:kernel6.18-debuginfo, p-cpe:/a:amazon:linux:bpftool6.18, p-cpe:/a:amazon:linux:kernel6.18-debuginfo-common-x86_64, p-cpe:/a:amazon:linux:python3-perf6.18

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

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 5/5/2026

Vulnerability Publication Date: 4/22/2026

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

Exploitable With

Core Impact

Metasploit (Copy Fail AF_ALG + authencesn Page-Cache Write)

Reference Information

CVE: CVE-2026-31431, CVE-2026-31677, CVE-2026-43033, CVE-2026-43043, CVE-2026-43077, CVE-2026-43078

IAVA: 2026-A-0428

Detections

Analytics