UBUNTU-CVE-2026-44898

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Source
https://ubuntu.com/security/CVE-2026-44898
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-44898.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-44898
Upstream
  • CVE-2026-44898
Published
2026-05-26T21:16:00Z
Modified
2026-05-27T19:15:29.083994863Z
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

Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.2.1, rendertocul() builds a <ul> table-of-contents tree from a list of (level, id, text) tuples. Both the id value (used as href="#<id>") and the text value (used as the visible link label) are inserted into <a> tags via a plain Python format string — with no HTML escaping applied to either value. When heading IDs are derived from user-supplied heading text (the standard use-case for readable slug anchors), an attacker can craft a heading whose text breaks out of the href="#..." attribute context, injecting arbitrary HTML tags including <script> blocks directly into the rendered TOC. This vulnerability is fixed in 3.2.1.

References

Affected packages

Ubuntu:16.04:LTS
mistune

Package

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

Affected ranges

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

Affected versions

0.*
0.6-2
0.7.1-1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "0.7.1-1",
            "binary_name": "python-mistune"
        },
        {
            "binary_version": "0.7.1-1",
            "binary_name": "python3-mistune"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-44898.json"
Ubuntu:18.04:LTS
mistune

Package

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

Affected ranges

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

Affected versions

0.*
0.7.4-1
0.8-1
0.8.1-1
0.8.3-2

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "0.8.3-2",
            "binary_name": "python-mistune"
        },
        {
            "binary_version": "0.8.3-2",
            "binary_name": "python3-mistune"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-44898.json"
Ubuntu:20.04:LTS
mistune

Package

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

Affected ranges

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

Affected versions

0.*
0.8.4-1
0.8.4-2

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "0.8.4-2",
            "binary_name": "python3-mistune"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-44898.json"
Ubuntu:22.04:LTS
mistune

Package

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

Affected ranges

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

Affected versions

0.*
0.8.4-4
0.8.4-5
2.*
2.0.0-1+really0.8.4-1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "2.0.0-1+really0.8.4-1",
            "binary_name": "python3-mistune"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-44898.json"
mistune0

Package

Name
mistune0
Purl
pkg:deb/ubuntu/mistune0?arch=source&distro=jammy

Affected ranges

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

Affected versions

0.*
0.8.4-1
0.8.4-2

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "0.8.4-2",
            "binary_name": "python3-mistune0"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-44898.json"
Ubuntu:24.04:LTS
mistune

Package

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

Affected ranges

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

Affected versions

2.*
2.0.4-2
3.*
3.0.2-1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "3.0.2-1",
            "binary_name": "python3-mistune"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-44898.json"
mistune0

Package

Name
mistune0
Purl
pkg:deb/ubuntu/mistune0?arch=source&distro=noble

Affected ranges

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

Affected versions

0.*
0.8.4-2

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "0.8.4-2",
            "binary_name": "python3-mistune0"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-44898.json"
Ubuntu:25.10
mistune

Package

Name
mistune
Purl
pkg:deb/ubuntu/mistune?arch=source&distro=questing

Affected ranges

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

Affected versions

3.*
3.0.2-2
3.1.3-1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "3.1.3-1",
            "binary_name": "python3-mistune"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-44898.json"
mistune0

Package

Name
mistune0
Purl
pkg:deb/ubuntu/mistune0?arch=source&distro=questing

Affected ranges

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

Affected versions

0.*
0.8.4-4

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "0.8.4-4",
            "binary_name": "python3-mistune0"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-44898.json"
Ubuntu:26.04:LTS
mistune

Package

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

Affected ranges

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

Affected versions

3.*
3.1.3-1
3.1.4-1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "3.1.4-1",
            "binary_name": "python3-mistune"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-44898.json"
mistune0

Package

Name
mistune0
Purl
pkg:deb/ubuntu/mistune0?arch=source&distro=resolute

Affected ranges

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

Affected versions

0.*
0.8.4-4
0.8.4-5
0.8.4-6

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "0.8.4-6",
            "binary_name": "python3-mistune0"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-44898.json"