UBUNTU-CVE-2026-49855

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Source
https://ubuntu.com/security/CVE-2026-49855
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-49855.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-49855
Upstream
Published
2026-07-14T21:17:00Z
Modified
2026-07-15T19:48:20.633047721Z
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
  • Ubuntu - medium
Summary
[none]
Details

Tornado is a Python web framework and asynchronous networking library. Prior to 6.5.6, Tornado gzip decompression routines processed limited-size chunks but did not enforce an overall limit on accumulated decompressed chunks, allowing a malicious server accessed by SimpleAsyncHTTPClient or an HTTPServer configured with decompress_request=True to consume effectively unlimited memory. This issue is fixed in version 6.5.6.

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
0Unknown introduced version / All previous versions are affected

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

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "6.4.0-1ubuntu0.5",
            "binary_name": "python3-tornado"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-49855.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
0Unknown introduced version / All previous versions are affected

Affected versions

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

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "6.5.4-0.1ubuntu0.1",
            "binary_name": "python3-tornado"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-49855.json"
Ubuntu:Pro:16.04:LTS
python-tornado

Package

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

Affected ranges

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

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

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "4.2.1-1ubuntu3.1+esm3",
            "binary_name": "python-tornado"
        },
        {
            "binary_version": "4.2.1-1ubuntu3.1+esm3",
            "binary_name": "python3-tornado"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-49855.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
0Unknown introduced version / All previous versions are affected

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

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "4.5.3-1ubuntu0.2+esm3",
            "binary_name": "python-tornado"
        },
        {
            "binary_version": "4.5.3-1ubuntu0.2+esm3",
            "binary_name": "python3-tornado"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-49855.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
0Unknown introduced version / All previous versions are affected

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

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "6.0.3+really5.1.1-3ubuntu0.1~esm5",
            "binary_name": "python3-tornado"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-49855.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
0Unknown introduced version / All previous versions are affected

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

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "6.1.0-3ubuntu0.1~esm5",
            "binary_name": "python3-tornado"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-49855.json"