CVE-2023-54397CWE-444

CVE-2023-54397

High · published September 15, 2026

CVSS v3.1
7.5
EPSS
0%
Percentile
30.5
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
7.5 · HIGH
Vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:H/A:N
CVSS v4.0
9.0 · 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
EPSS
0.00377 · 30.5th percentile
Weakness
CWE-444 · Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
Published
2026-09-15T20:17Z
References (2)
https://github.com/tornadoweb/tornado/security/advisories/GHSA-qppv-j76h-2rpx · [email protected]https://www.vulncheck.com/advisories/tornado-before-6.3.3-http-request-smuggling-via-content-length · [email protected]
EPSS history
Timeline
  • 17 SEP 03:19Z
    EPSS moved — → 0%
    epss
  • 15 SEP 15:17Z
    Tornado before 6.3.3 HTTP Request Smuggling via Content-Length
    cvelistv5