USN-8952-2

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Source
https://ubuntu.com/security/notices/USN-8952-2
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-8952-2.json
JSON Data
https://api.osv.dev/v1/vulns/USN-8952-2
Upstream
Related
Published
2026-11-06T15:04:17Z
Modified
2026-11-07T01:58:36Z
Summary
python-tornado regression
Details

USN-8952-1 fixed vulnerabilities in Tornado. Unfortunately that update was incomplete due to an incomplete fix for CVE-2026-103263, which broke static file serving for applications that subclass Tornado's StaticFileHandler, such as Jupyter, and could introduce a regression. This update fixes the problem.

We apologize for the inconvenience.

Original advisory details:

It was discovered that Tornado did not properly handle certain HTTP requests and network inputs. An attacker could possibly use these issues to cause a denial of service, expose sensitive information, or bypass access controls.

(CVE-2023-54397, CVE-2024-14029, CVE-2026-91990, CVE-2026-91992, CVE-2026-103262, CVE-2026-103263)

References

Affected packages

Ubuntu:24.04:LTS
python-tornado

Package

Name
python-tornado
Purl
pkg:deb/ubuntu/python-tornado?arch=source&distro=noble

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
6.4.0-1ubuntu0.7

Affected versions

6.*
6.3.2-1
6.4.0-0ubuntu1
6.4.0-1
6.4.0-1build1
6.4.0-1ubuntu0.1
6.4.0-1ubuntu0.2
6.4.0-1ubuntu0.4
6.4.0-1ubuntu0.5
6.4.0-1ubuntu0.6

Ecosystem specific 

{
    "availability": "No subscription required",
    "binaries": [
        {
            "binary_name": "python3-tornado",
            "binary_version": "6.4.0-1ubuntu0.7"
        }
    ]
}

Database specific

cves_map 
{
    "cves": [
        {
            "id": "CVE-2026-103263",
            "severity": [
                {
                    "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N",
                    "type": "CVSS_V3"
                },
                {
                    "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N",
                    "type": "CVSS_V4"
                },
                {
                    "score": "medium",
                    "type": "Ubuntu"
                }
            ]
        }
    ],
    "ecosystem": "Ubuntu:24.04:LTS"
}
source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-8952-2.json"
Ubuntu:26.04:LTS
python-tornado

Package

Name
python-tornado
Purl
pkg:deb/ubuntu/python-tornado?arch=source&distro=resolute

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
6.5.4-0.1ubuntu0.3

Affected versions

6.*
6.4.2-3
6.5.2-3
6.5.4-0.1
6.5.4-0.1ubuntu0.1
6.5.4-0.1ubuntu0.2

Ecosystem specific 

{
    "availability": "No subscription required",
    "binaries": [
        {
            "binary_name": "python3-tornado",
            "binary_version": "6.5.4-0.1ubuntu0.3"
        }
    ]
}

Database specific

cves_map 
{
    "cves": [
        {
            "id": "CVE-2026-103263",
            "severity": [
                {
                    "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N",
                    "type": "CVSS_V3"
                },
                {
                    "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N",
                    "type": "CVSS_V4"
                },
                {
                    "score": "medium",
                    "type": "Ubuntu"
                }
            ]
        }
    ],
    "ecosystem": "Ubuntu:26.04:LTS"
}
source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-8952-2.json"
Ubuntu:26.10
python-tornado

Package

Name
python-tornado
Purl
pkg:deb/ubuntu/python-tornado?arch=source&distro=stonking

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
6.5.5-5ubuntu1.2

Affected versions

6.*
6.5.4-0.1
6.5.5-2
6.5.5-4
6.5.5-5
6.5.5-5ubuntu1.1

Ecosystem specific 

{
    "availability": "No subscription required",
    "binaries": [
        {
            "binary_name": "python3-tornado",
            "binary_version": "6.5.5-5ubuntu1.2"
        }
    ]
}

Database specific

cves_map 
{
    "cves": [
        {
            "id": "CVE-2026-103263",
            "severity": [
                {
                    "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N",
                    "type": "CVSS_V3"
                },
                {
                    "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N",
                    "type": "CVSS_V4"
                },
                {
                    "score": "medium",
                    "type": "Ubuntu"
                }
            ]
        }
    ],
    "ecosystem": "Ubuntu:26.10"
}
source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-8952-2.json"
Ubuntu:Pro:16.04:LTS
python-tornado

Package

Name
python-tornado
Purl
pkg:deb/ubuntu/python-tornado?arch=source&distro=esm-infra-legacy%2Fxenial

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
4.2.1-1ubuntu3.1+esm5

Affected versions

4.*
4.2.1-1ubuntu2
4.2.1-1ubuntu3
4.2.1-1ubuntu3.1
4.2.1-1ubuntu3.1+esm1
4.2.1-1ubuntu3.1+esm2
4.2.1-1ubuntu3.1+esm3
4.2.1-1ubuntu3.1+esm4

Ecosystem specific 

{
    "availability": "Available with Ubuntu Pro with Legacy support add-on: https://ubuntu.com/pro",
    "binaries": [
        {
            "binary_name": "python-tornado",
            "binary_version": "4.2.1-1ubuntu3.1+esm5"
        },
        {
            "binary_name": "python3-tornado",
            "binary_version": "4.2.1-1ubuntu3.1+esm5"
        }
    ]
}

Database specific

cves_map 
{
    "cves": [
        {
            "id": "CVE-2026-103263",
            "severity": [
                {
                    "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N",
                    "type": "CVSS_V3"
                },
                {
                    "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N",
                    "type": "CVSS_V4"
                },
                {
                    "score": "medium",
                    "type": "Ubuntu"
                }
            ]
        }
    ],
    "ecosystem": "Ubuntu:Pro:16.04:LTS"
}
source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-8952-2.json"
Ubuntu:Pro:18.04:LTS
python-tornado

Package

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

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
4.5.3-1ubuntu0.2+esm5

Affected versions

4.*
4.5.1-2.1~build2
4.5.2-1
4.5.3-1
4.5.3-1ubuntu0.1
4.5.3-1ubuntu0.2
4.5.3-1ubuntu0.2+esm1
4.5.3-1ubuntu0.2+esm2
4.5.3-1ubuntu0.2+esm3
4.5.3-1ubuntu0.2+esm4

Ecosystem specific 

{
    "availability": "Available with Ubuntu Pro: https://ubuntu.com/pro",
    "binaries": [
        {
            "binary_name": "python-tornado",
            "binary_version": "4.5.3-1ubuntu0.2+esm5"
        },
        {
            "binary_name": "python3-tornado",
            "binary_version": "4.5.3-1ubuntu0.2+esm5"
        }
    ]
}

Database specific

cves_map 
{
    "cves": [
        {
            "id": "CVE-2026-103263",
            "severity": [
                {
                    "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N",
                    "type": "CVSS_V3"
                },
                {
                    "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N",
                    "type": "CVSS_V4"
                },
                {
                    "score": "medium",
                    "type": "Ubuntu"
                }
            ]
        }
    ],
    "ecosystem": "Ubuntu:Pro:18.04:LTS"
}
source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-8952-2.json"
Ubuntu:Pro:20.04:LTS
python-tornado

Package

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

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
6.0.3+really5.1.1-3ubuntu0.1~esm8

Affected versions

5.*
5.1.1-4ubuntu1
5.1.1-4ubuntu5
6.*
6.0.3+really5.1.1-2
6.0.3+really5.1.1-2build1
6.0.3+really5.1.1-2build2
6.0.3+really5.1.1-3
6.0.3+really5.1.1-3ubuntu0.1~esm1
6.0.3+really5.1.1-3ubuntu0.1~esm3
6.0.3+really5.1.1-3ubuntu0.1~esm5
6.0.3+really5.1.1-3ubuntu0.1~esm7

Ecosystem specific 

{
    "availability": "Available with Ubuntu Pro: https://ubuntu.com/pro",
    "binaries": [
        {
            "binary_name": "python3-tornado",
            "binary_version": "6.0.3+really5.1.1-3ubuntu0.1~esm8"
        }
    ]
}

Database specific

cves_map 
{
    "cves": [
        {
            "id": "CVE-2026-103263",
            "severity": [
                {
                    "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N",
                    "type": "CVSS_V3"
                },
                {
                    "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N",
                    "type": "CVSS_V4"
                },
                {
                    "score": "medium",
                    "type": "Ubuntu"
                }
            ]
        }
    ],
    "ecosystem": "Ubuntu:Pro:20.04:LTS"
}
source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-8952-2.json"
Ubuntu:Pro:22.04:LTS
python-tornado

Package

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

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
6.1.0-3ubuntu0.1~esm7

Affected versions

6.*
6.1.0-1build1
6.1.0-2
6.1.0-3
6.1.0-3build1
6.1.0-3ubuntu0.1~esm1
6.1.0-3ubuntu0.1~esm2
6.1.0-3ubuntu0.1~esm4
6.1.0-3ubuntu0.1~esm5
6.1.0-3ubuntu0.1~esm6

Ecosystem specific 

{
    "availability": "Available with Ubuntu Pro: https://ubuntu.com/pro",
    "binaries": [
        {
            "binary_name": "python3-tornado",
            "binary_version": "6.1.0-3ubuntu0.1~esm7"
        }
    ]
}

Database specific

cves_map 
{
    "cves": [
        {
            "id": "CVE-2026-103263",
            "severity": [
                {
                    "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N",
                    "type": "CVSS_V3"
                },
                {
                    "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N",
                    "type": "CVSS_V4"
                },
                {
                    "score": "medium",
                    "type": "Ubuntu"
                }
            ]
        }
    ],
    "ecosystem": "Ubuntu:Pro:22.04:LTS"
}
source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/usn/USN-8952-2.json"