Amazon Linux 2 : yelp, --advisory ALAS2-2026-3821 (ALAS-2026-3821)

medium Nessus Plugin ID 328823

Synopsis

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

Description

The version of yelp installed on the remote host is prior to 3.28.1-1. It is, therefore, affected by a vulnerability as referenced in the ALAS2-2026-3821 advisory.

A flaw was found in Yelp due to an overly permissive Content Security Policy (CSP) implementation provided by yelp-xsl. A malicious Flatpak application can open crafted help content through the OpenURI portal. By embedding an untrusted CSS stylesheet within a structured SVG document, attacker-controlled content can bypass Flatpak's intended sandbox isolation, allowing Yelp to evaluate local XML inclusions and disclose arbitrary user-readable host files through remote CSS resource requests. This may result in the unauthorized disclosure of sensitive information. (CVE-2026-13601)

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

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

Solution

Run 'yum update yelp' or or 'yum update --advisory ALAS2-2026-3821' to update your system.

Plugin Details

Severity: Medium

ID: 328823

File Name: al2_ALAS-2026-3821.nasl

Version: 1.1

Type: Local

Agent: unix

Family: Amazon Linux Local Security Checks

Published: 7/21/2026

Updated: 7/21/2026

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: Low

Score: 3.3

Percentile: 51.2

CVSS v2

Risk Factor: Medium

Base Score: 4.6

Temporal Score: 3.4

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

CVSS Score Source: CVE-2026-13601

CVSS v3

Risk Factor: Medium

Base Score: 6.5

Temporal Score: 5.7

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

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

Vulnerability Information

CPE: cpe:/o:amazon:linux:2, p-cpe:/a:amazon:linux:yelp-debuginfo, p-cpe:/a:amazon:linux:yelp-devel, p-cpe:/a:amazon:linux:yelp-libs, p-cpe:/a:amazon:linux:yelp

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

Exploit Ease: No known exploits are available

Patch Publication Date: 7/20/2026

Vulnerability Publication Date: 6/29/2026

Reference Information

CVE: CVE-2026-13601

Detections

Analytics