UBUNTU-CVE-2026-33231

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Source
https://ubuntu.com/security/CVE-2026-33231
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-33231.json
JSON Data
https://api.test.osv.dev/v1/vulns/UBUNTU-CVE-2026-33231
Upstream
Downstream
Related
Published
2026-03-20T23:16:00Z
Modified
2026-06-30T18:16:15.092361010Z
Severity
  • 7.5 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
  • 7.5 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

NLTK (Natural Language Toolkit) is a suite of open source Python modules, data sets, and tutorials supporting research and development in Natural Language Processing. In versions 3.9.3 and prior, nltk.app.wordnet_app allows unauthenticated remote shutdown of the local WordNet Browser HTTP server when it is started in its default mode. A simple GET /SHUTDOWN%20THE%20SERVER request causes the process to terminate immediately via os._exit(0), resulting in a denial of service. Commit bbaae83db86a0f49e00f5b0db44a7254c268de9b patches the issue.

References

Affected packages

Ubuntu:25.10
nltk

Package

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

Affected ranges

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

Affected versions

3.*
3.9.1-2

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "3.9.1-2",
            "binary_name": "python3-nltk"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-33231.json"
Ubuntu:Pro:14.04:LTS
nltk

Package

Name
nltk
Purl
pkg:deb/ubuntu/nltk?arch=source&distro=esm-infra-legacy%2Ftrusty

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
2.0~b9-0ubuntu4.1~esm6

Affected versions

2.*
2.0~b9-0ubuntu4
2.0~b9-0ubuntu4.1~esm2
2.0~b9-0ubuntu4.1~esm4
2.0~b9-0ubuntu4.1~esm5

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "2.0~b9-0ubuntu4.1~esm6",
            "binary_name": "python-nltk"
        }
    ],
    "availability": "Available with Ubuntu Pro with Legacy support add-on: https://ubuntu.com/pro"
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-33231.json"
Ubuntu:Pro:16.04:LTS
nltk

Package

Name
nltk
Purl
pkg:deb/ubuntu/nltk?arch=source&distro=esm-apps-legacy%2Fxenial

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
3.1-1ubuntu0.1+esm4

Affected versions

3.*
3.0.4-1
3.0.5-1
3.1-1
3.1-1ubuntu0.1
3.1-1ubuntu0.1+esm1
3.1-1ubuntu0.1+esm2
3.1-1ubuntu0.1+esm3

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "3.1-1ubuntu0.1+esm4",
            "binary_name": "python-nltk"
        },
        {
            "binary_version": "3.1-1ubuntu0.1+esm4",
            "binary_name": "python3-nltk"
        }
    ],
    "availability": "Available with Ubuntu Pro with Legacy support add-on: https://ubuntu.com/pro"
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-33231.json"
Ubuntu:Pro:18.04:LTS
nltk

Package

Name
nltk
Purl
pkg:deb/ubuntu/nltk?arch=source&distro=esm-apps%2Fbionic

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
3.2.5-1ubuntu0.1+esm4

Affected versions

3.*
3.2.4-1
3.2.5-1
3.2.5-1ubuntu0.1
3.2.5-1ubuntu0.1+esm1
3.2.5-1ubuntu0.1+esm2
3.2.5-1ubuntu0.1+esm3

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "3.2.5-1ubuntu0.1+esm4",
            "binary_name": "python-nltk"
        },
        {
            "binary_version": "3.2.5-1ubuntu0.1+esm4",
            "binary_name": "python3-nltk"
        }
    ],
    "availability": "Available with Ubuntu Pro: https://ubuntu.com/pro"
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-33231.json"
Ubuntu:Pro:20.04:LTS
nltk

Package

Name
nltk
Purl
pkg:deb/ubuntu/nltk?arch=source&distro=esm-apps%2Ffocal

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
3.4.5-2ubuntu0.1~esm4

Affected versions

3.*
3.4.5-1
3.4.5-2
3.4.5-2ubuntu0.1~esm1
3.4.5-2ubuntu0.1~esm2
3.4.5-2ubuntu0.1~esm3

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "3.4.5-2ubuntu0.1~esm4",
            "binary_name": "python3-nltk"
        }
    ],
    "availability": "Available with Ubuntu Pro: https://ubuntu.com/pro"
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-33231.json"
Ubuntu:Pro:22.04:LTS
nltk

Package

Name
nltk
Purl
pkg:deb/ubuntu/nltk?arch=source&distro=esm-apps%2Fjammy

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
3.7-1ubuntu0.1~esm2

Affected versions

3.*
3.5-1
3.6.5-1
3.6.7-1
3.7-1
3.7-1ubuntu0.1~esm1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "3.7-1ubuntu0.1~esm2",
            "binary_name": "python3-nltk"
        }
    ],
    "availability": "Available with Ubuntu Pro: https://ubuntu.com/pro"
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-33231.json"
Ubuntu:Pro:24.04:LTS
nltk

Package

Name
nltk
Purl
pkg:deb/ubuntu/nltk?arch=source&distro=esm-apps%2Fnoble

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
3.8.1-1ubuntu0.1~esm2

Affected versions

3.*
3.8.1-1
3.8.1-1ubuntu0.1~esm1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "3.8.1-1ubuntu0.1~esm2",
            "binary_name": "python3-nltk"
        }
    ],
    "availability": "Available with Ubuntu Pro: https://ubuntu.com/pro"
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-33231.json"
Ubuntu:Pro:26.04:LTS
nltk

Package

Name
nltk
Purl
pkg:deb/ubuntu/nltk?arch=source&distro=esm-apps%2Fresolute

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
3.9.2-1ubuntu0.1~esm2

Affected versions

3.*
3.9.1-2
3.9.1-2build1
3.9.2-1
3.9.2-1ubuntu0.1~esm1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "3.9.2-1ubuntu0.1~esm2",
            "binary_name": "python3-nltk"
        }
    ],
    "availability": "Available with Ubuntu Pro: https://ubuntu.com/pro"
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-33231.json"