UBUNTU-CVE-2026-80205

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Source
https://ubuntu.com/security/CVE-2026-80205
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-80205.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-80205
Upstream
Published
2026-08-26T11:16:00Z
Modified
2026-09-02T19:36:34.420949379Z
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
  • 8.7 (High) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

NLTK versions before 3.10.0 contain a regular expression denial of service vulnerability in Text.findall() and TokenSearcher.findall() methods that accept user-supplied regular expressions without validation or timeout. Attackers can supply crafted regex patterns that cause catastrophic backtracking, resulting in indefinite CPU saturation and denial of service to all users of the Python process.

References

Affected packages

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

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
2.0~b9-0ubuntu4.1~esm6

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "python-nltk",
            "binary_version": "2.0~b9-0ubuntu4.1~esm6"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-80205.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

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
3.1-1ubuntu0.1+esm4

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "python-nltk",
            "binary_version": "3.1-1ubuntu0.1+esm4"
        },
        {
            "binary_name": "python3-nltk",
            "binary_version": "3.1-1ubuntu0.1+esm4"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-80205.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

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
3.2.5-1ubuntu0.1+esm4

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "python-nltk",
            "binary_version": "3.2.5-1ubuntu0.1+esm4"
        },
        {
            "binary_name": "python3-nltk",
            "binary_version": "3.2.5-1ubuntu0.1+esm4"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-80205.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

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
3.4.5-2ubuntu0.1~esm4

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "python3-nltk",
            "binary_version": "3.4.5-2ubuntu0.1~esm4"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-80205.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

Affected versions

3.*
3.5-1
3.6.5-1
3.6.7-1
3.7-1
3.7-1ubuntu0.1~esm1
3.7-1ubuntu0.1~esm2

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "python3-nltk",
            "binary_version": "3.7-1ubuntu0.1~esm2"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-80205.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

Affected versions

3.*
3.8.1-1
3.8.1-1ubuntu0.1~esm1
3.8.1-1ubuntu0.1~esm2

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "python3-nltk",
            "binary_version": "3.8.1-1ubuntu0.1~esm2"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-80205.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

Affected versions

3.*
3.9.1-2
3.9.1-2build1
3.9.2-1
3.9.2-1ubuntu0.1~esm1
3.9.2-1ubuntu0.1~esm2

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "python3-nltk",
            "binary_version": "3.9.2-1ubuntu0.1~esm2"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-80205.json"