CriticalFix available
python-tornado — security advisory
Tornado before 6.3.3 contains an HTTP request smuggling vulnerability due to improper parsing of Content-Length headers accepting non-standard characters. Attackers can send crafted HTTP requests with these characters to bypass proxy validation and smuggle requests when deployed behind certain proxies.
- Products
- python-tornado
- Affected versions
- 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, 4.5.1-2.1~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, 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
- Fixed versions
- 4.2.1-1ubuntu3.1+esm4, 4.5.3-1ubuntu0.2+esm4, 6.1.0-3ubuntu0.1~esm6
- CVEs
- CVE-2023-54397
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 19:30 UTC · Revision 1
Source evidence
Tornado before 6.3.3 contains an HTTP request smuggling vulnerability due to improper parsing of Content-Length headers accepting non-standard characters. Attackers can send crafted HTTP requests with these characters to bypass proxy validation and smuggle requests when deployed behind certain proxies.
osv:UBUNTU-CVE-2023-54397
python-tornado
Fixed versions: 4.2.1-1ubuntu3.1+esm4
python-tornado
Fixed versions: 4.5.3-1ubuntu0.2+esm4
python-tornado
Fixed versions: 6.1.0-3ubuntu0.1~esm6
Complete source record
{
"id": "63d99c44ebbe5fcb641d9357be84c739bcb6772fb8cafa13a035bd89a33b2599",
"url": "https://osv.dev/vulnerability/UBUNTU-CVE-2023-54397",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "UBUNTU-CVE-2023-54397",
"summary": "Tornado before 6.3.3 contains an HTTP request smuggling vulnerability due to improper parsing of Content-Length headers accepting non-standard characters. Attackers can send crafted HTTP requests with these characters to bypass proxy validation and smuggle requests when deployed behind certain proxies.",
"evidence": "osv:UBUNTU-CVE-2023-54397",
"products": [
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"name": {
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"affected_versions": [
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{
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{
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"evidence": "/affected/1/versions"
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{
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"evidence": "/affected/1/versions"
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{
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{
"name": {
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"value": "6.1.0-3ubuntu0.1~esm6",
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"affected_versions": [
{
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"evidence": "/affected/2/versions"
},
{
"value": "6.1.0-2",
"evidence": "/affected/2/versions"
},
{
"value": "6.1.0-3",
"evidence": "/affected/2/versions"
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{
"value": "6.1.0-3build1",
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{
"value": "6.1.0-3ubuntu0.1~esm1",
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{
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{
"value": "6.1.0-3ubuntu0.1~esm4",
"evidence": "/affected/2/versions"
},
{
"value": "6.1.0-3ubuntu0.1~esm5",
"evidence": "/affected/2/versions"
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],
"severity": "critical",
"structured": {
"id": "UBUNTU-CVE-2023-54397",
"aliases": [
"UBUNTU-CVE-2023-54397"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:H/A:N"
},
{
"type": "CVSS_V4",
"score": "CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:L/VI:H/VA:N/SC:L/SI:H/SA:N"
},
{
"type": "Ubuntu",
"score": "medium"
}
],
"affected": [
{
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{
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"events": [
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"package": {
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"versions": [
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"4.2.1-1ubuntu3.1",
"4.2.1-1ubuntu3.1+esm1",
"4.2.1-1ubuntu3.1+esm2",
"4.2.1-1ubuntu3.1+esm3"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2023/UBUNTU-CVE-2023-54397.json"
},
"ecosystem_specific": {
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},
{
"binary_name": "python3-tornado",
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"availability": "Available with Ubuntu Pro with Legacy support add-on: https://ubuntu.com/pro"
}
},
{
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],
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},
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"4.5.2-1",
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"4.5.3-1ubuntu0.2+esm1",
"4.5.3-1ubuntu0.2+esm2",
"4.5.3-1ubuntu0.2+esm3"
],
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{
"binary_name": "python3-tornado",
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},
{
"ranges": [
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],
"package": {
"name": "python-tornado",
"purl": "pkg:deb/ubuntu/python-tornado?arch=source&distro=esm-apps%2Fjammy",
"ecosystem": "Ubuntu:Pro:22.04:LTS"
},
"versions": [
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"6.1.0-2",
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],
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}
}
],
"modified": "2026-10-22T23:19:27.650071385Z",
"provider": "osv",
"upstream": [
"CVE-2023-54397"
],
"references": [
"https://ubuntu.com/security/CVE-2023-54397",
"https://www.cve.org/CVERecord?id=CVE-2023-54397",
"https://ubuntu.com/security/notices/USN-8952-1"
]
},
"related_cves": [
{
"value": "CVE-2023-54397",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/1/score"
},
"source_id": "core-osv",
"document_id": 410105,
"published_at": "2026-09-15T16:17:00+00:00"
}