Amazon Linux 2 : qemu (ALAS-2026-4027)

high Nessus Plugin ID 371773

Synopsis

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

Description

The version of qemu installed on the remote host is prior to 3.1.0-8. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2-2026-4027 advisory.

hw/display/qxl: validate primary surface stride against width (CVE-2026-16271)

hw/usb/hcd-xhci: Set reentrancy guard in timer functions (CVE-2026-17588)

hw/display/vga: fix text-mode OOB write after a graphics surface switch (CVE-2026-77913)

io/channel-socket: do not treat a zero length write as an error (CVE-2026-84788)

A use-after-free vulnerability was found in QEMU's 9pfs subsystem. A race condition between the main thread and a worker thread when processing concurrent Tlcreate and Twalk requests allows a malicious guest user to craft a fid path containing stale heap data, bypassing directory traversal restrictions and escaping the shared directory boundary. This can lead to arbitrary host file read/write and code execution (VM escape) as the QEMU process user. (CVE-2026-93834)

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 'yum update qemu' or or 'yum update --advisory ALAS2-2026-4027' to update your system.

Plugin Details

Severity: High

ID: 371773

File Name: al2_ALAS-2026-4027.nasl

Version: 1.1

Type: Local

Agent: unix

Family: Amazon Linux Local Security Checks

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: 5

Percentile: 92.98

CVSS v2

Risk Factor: Medium

Base Score: 6.8

Temporal Score: 5

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

CVSS Score Source: CVE-2026-93834

CVSS v3

Risk Factor: High

Base Score: 8.8

Temporal Score: 7.7

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

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

Vulnerability Information

CPE: cpe:/o:amazon:linux:2, p-cpe:/a:amazon:linux:ivshmem-tools, p-cpe:/a:amazon:linux:qemu-audio-alsa, p-cpe:/a:amazon:linux:qemu-audio-oss, p-cpe:/a:amazon:linux:qemu-audio-pa, p-cpe:/a:amazon:linux:qemu-audio-sdl, p-cpe:/a:amazon:linux:qemu-block-curl, p-cpe:/a:amazon:linux:qemu-block-dmg, p-cpe:/a:amazon:linux:qemu-block-iscsi, p-cpe:/a:amazon:linux:qemu-block-nfs, p-cpe:/a:amazon:linux:qemu-block-rbd, p-cpe:/a:amazon:linux:qemu-block-ssh, p-cpe:/a:amazon:linux:qemu-common, p-cpe:/a:amazon:linux:qemu-debuginfo, p-cpe:/a:amazon:linux:qemu-guest-agent, p-cpe:/a:amazon:linux:qemu-img, p-cpe:/a:amazon:linux:qemu-kvm-core, p-cpe:/a:amazon:linux:qemu-kvm, p-cpe:/a:amazon:linux:qemu-system-aarch64-core, p-cpe:/a:amazon:linux:qemu-system-aarch64, p-cpe:/a:amazon:linux:qemu-system-x86-core, p-cpe:/a:amazon:linux:qemu-system-x86, p-cpe:/a:amazon:linux:qemu-ui-curses, p-cpe:/a:amazon:linux:qemu-ui-gtk, p-cpe:/a:amazon:linux:qemu-ui-sdl, p-cpe:/a:amazon:linux:qemu-user-binfmt, p-cpe:/a:amazon:linux:qemu-user-static, p-cpe:/a:amazon:linux:qemu-user, p-cpe:/a:amazon:linux:qemu

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: 9/25/2026

Reference Information

CVE: CVE-2026-16271, CVE-2026-17588, CVE-2026-77913, CVE-2026-84788, CVE-2026-93834

Detections

Analytics