Ubuntu 20.04 LTS / 22.04 LTS / 24.04 LTS : league/commonmark vulnerabilities (USN-8194-1)

medium Nessus Plugin ID 309186

Synopsis

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

Description

The remote Ubuntu 20.04 LTS / 22.04 LTS / 24.04 LTS host has a package installed that is affected by multiple vulnerabilities as referenced in the USN-8194-1 advisory.

It was discovered that league/commonmark did not properly restrict unsafe attributes when the Attributes extension was enabled. An attacker could possibly use this issue to cause cross-site scripting by injecting malicious code into rendered HTML. This issue only affected Ubuntu 22.04 LTS and Ubuntu 24.04 LTS. (CVE-2025-46734)

It was discovered that league/commonmark did not properly block certain disallowed HTML tags in some cases. An attacker could possibly use this issue to cause cross-site scripting by inserting malicious HTML that bypassed filtering. (CVE-2026-30838)

It was discovered that league/commonmark did not properly enforce domain allowlist checks in the Embed extension. An attacker could possibly use this issue to bypass domain restrictions and cause untrusted content to be treated as allowed. This issue only affected Ubuntu 24.04 LTS. (CVE-2026-33347)

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 php-league-commonmark package.

See Also

https://ubuntu.com/security/notices/USN-8194-1

Plugin Details

Severity: Medium

ID: 309186

File Name: ubuntu_USN-8194-1.nasl

Version: 1.1

Type: Local

Agent: unix

Published: 4/22/2026

Updated: 4/22/2026

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

Risk Information

VPR

Risk Factor: Low

Score: 3.8

CVSS v2

Risk Factor: Medium

Base Score: 6.4

Temporal Score: 4.7

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

CVSS Score Source: CVE-2026-33347

CVSS v3

Risk Factor: Medium

Base Score: 6.1

Temporal Score: 5.3

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

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

CVSS v4

Risk Factor: Medium

Base Score: 6.3

Threat Score: 1.7

Threat Vector: CVSS:4.0/E:U

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

Vulnerability Information

CPE: p-cpe:/a:canonical:ubuntu_linux:php-league-commonmark, cpe:/o:canonical:ubuntu_linux:20.04:-:lts, cpe:/o:canonical:ubuntu_linux:24.04:-:lts, cpe:/o:canonical:ubuntu_linux:22.04:-:lts

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

Exploit Ease: No known exploits are available

Patch Publication Date: 4/21/2026

Vulnerability Publication Date: 5/5/2025

Reference Information

CVE: CVE-2025-46734, CVE-2026-30838, CVE-2026-33347

USN: 8194-1