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.
History

Tue, 29 Sep 2026 13:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

threat_severity

Critical


Thu, 17 Sep 2026 15:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Tue, 15 Sep 2026 15:30:00 +0000

Type Values Removed Values Added
Description 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.
Title Tornado before 6.3.3 HTTP Request Smuggling via Content-Length
First Time appeared Tornadoweb
Tornadoweb tornado
Weaknesses CWE-444
CPEs cpe:2.3:a:tornadoweb:tornado:*:*:*:*:*:*:*:*
Vendors & Products Tornadoweb
Tornadoweb tornado
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:H/A:N'}

cvssV4_0

{'score': 9, 'vector': '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'}


cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published: 2026-09-15T15:17:52.261Z

Updated: 2026-09-17T14:48:55.089Z

Reserved: 2026-09-15T11:12:19.647Z

Link: CVE-2023-54397

cve-icon Vulnrichment

Updated: 2026-09-17T14:48:45.855Z

cve-icon NVD

Status : Deferred

Published: 2026-09-15T16:17:05.777

Modified: 2026-09-17T15:16:39.103

Link: CVE-2023-54397

cve-icon Redhat

Severity : Critical

Publid Date: 2026-09-15T15:17:52Z

Links: CVE-2023-54397 - Bugzilla