UBUNTU-CVE-2026-71478

See a problem?
Please try reporting it to the source first.
Source
https://ubuntu.com/security/CVE-2026-71478
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-71478.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-71478
Upstream
Published
2026-08-07T00:00:00Z
Modified
2026-08-07T17:45:32.979759817Z
Severity
  • 6.1 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

league/commonmark is a PHP library for parsing and rendering CommonMark Markdown. From 1.5.0 until 2.9.0, the AttributesExtension's href and src unsafe-link filter can be bypassed by embedding control bytes, such as a tab, carriage return, line feed, or leading C0 control character, in a javascript: URL that browsers discard before parsing the scheme, causing the browser to still execute the script even when the unsafe-link filter is enabled. This issue is fixed in 2.9.0.

References

Affected packages

Ubuntu:16.04:LTS
markdown

Package

Name
markdown
Purl
pkg:deb/ubuntu/markdown?arch=source&distro=xenial

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

1.*
1.0.1-7
1.0.1-8

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "1.0.1-8",
            "binary_name": "markdown"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-71478.json"
Ubuntu:18.04:LTS
markdown

Package

Name
markdown
Purl
pkg:deb/ubuntu/markdown?arch=source&distro=bionic

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

1.*
1.0.1-9
1.0.1-10

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "1.0.1-10",
            "binary_name": "markdown"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-71478.json"
Ubuntu:20.04:LTS
markdown

Package

Name
markdown
Purl
pkg:deb/ubuntu/markdown?arch=source&distro=focal

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

1.*
1.0.1-10

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "1.0.1-10",
            "binary_name": "markdown"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-71478.json"
Ubuntu:22.04:LTS
commonmark

Package

Name
commonmark
Purl
pkg:deb/ubuntu/commonmark?arch=source&distro=jammy

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

0.*
0.9.1-3

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "0.9.1-3",
            "binary_name": "python3-commonmark"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-71478.json"
markdown

Package

Name
markdown
Purl
pkg:deb/ubuntu/markdown?arch=source&distro=jammy

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

1.*
1.0.1-10.1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "1.0.1-10.1",
            "binary_name": "markdown"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-71478.json"
Ubuntu:24.04:LTS
commonmark

Package

Name
commonmark
Purl
pkg:deb/ubuntu/commonmark?arch=source&distro=noble

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

0.*
0.9.1-4
0.9.1-5

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "0.9.1-5",
            "binary_name": "python3-commonmark"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-71478.json"
markdown

Package

Name
markdown
Purl
pkg:deb/ubuntu/markdown?arch=source&distro=noble

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

1.*
1.0.1-12

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "1.0.1-12",
            "binary_name": "markdown"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-71478.json"
Ubuntu:26.04:LTS
commonmark

Package

Name
commonmark
Purl
pkg:deb/ubuntu/commonmark?arch=source&distro=resolute

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

0.*
0.9.1-8
0.9.1-8build1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "0.9.1-8build1",
            "binary_name": "python3-commonmark"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-71478.json"
markdown

Package

Name
markdown
Purl
pkg:deb/ubuntu/markdown?arch=source&distro=resolute

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

1.*
1.0.1-14

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "1.0.1-14",
            "binary_name": "markdown"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-71478.json"