Amazon Linux 2023 : corosync, corosync-vqsim, corosynclib (ALAS2023-2026-1560)

high Nessus Plugin ID 306238

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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 ALAS2023-2026-1560 advisory.

A flaw was found in Corosync. A remote unauthenticated attacker can exploit a wrong return value vulnerability in the Corosync membership commit token sanity check by sending a specially crafted User Datagram Protocol (UDP) packet. This can lead to an out-of-bounds read, causing a denial of service (DoS) and potentially disclosing limited memory contents. This vulnerability affects Corosync when running in totemudp/totemudpu mode, which is the default configuration. (CVE-2026-35091)

A flaw was found in Corosync. An integer overflow vulnerability in Corosync's join message sanity validation allows a remote, unauthenticated attacker to send crafted User Datagram Protocol (UDP) packets.
This can cause the service to crash, leading to a denial of service. This vulnerability specifically affects Corosync deployments configured to use totemudp/totemudpu mode. (CVE-2026-35092)

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 corosync --releasever 2023.11.20260413' or or 'dnf update --advisory ALAS2023-2026-1560 --releasever 2023.11.20260413' to update your system.

Plugin Details

Severity: High

ID: 306238

File Name: al2023_ALAS2023-2026-1560.nasl

Version: 1.1

Type: Local

Agent: unix

Family: Amazon Linux Local Security Checks

Published: 4/13/2026

Updated: 4/13/2026

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

Risk Information

VPR

Risk Factor: Low

Score: 3.5

Percentile: 51.77

CVSS v2

Risk Factor: High

Base Score: 8.5

Temporal Score: 6.7

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

CVSS Score Source: CVE-2026-35091

CVSS v3

Risk Factor: High

Base Score: 8.2

Temporal Score: 7.4

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

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

Vulnerability Information

CPE: p-cpe:/a:amazon:linux:corosync, p-cpe:/a:amazon:linux:corosynclib, p-cpe:/a:amazon:linux:corosync-vqsim-debuginfo, p-cpe:/a:amazon:linux:corosync-vqsim, p-cpe:/a:amazon:linux:corosynclib-debuginfo, p-cpe:/a:amazon:linux:corosync-debuginfo, p-cpe:/a:amazon:linux:corosynclib-devel, p-cpe:/a:amazon:linux:corosync-debugsource, cpe:/o:amazon:linux:2023

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: 4/13/2026

Vulnerability Publication Date: 4/1/2026

Reference Information

CVE: CVE-2026-35091, CVE-2026-35092

Detections

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