Vulnerability in Tornadoweb Tornado
CVE-2023-54397
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.
Vulnerability class: HTTP Request Smuggling
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:H/A:N.
EPSS exploit prediction
EPSS: 0.004 (31.7th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 32nd percentile — 31.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: +0.000
Affected products
Weakness classification (CWE)
References
- github.com/tornadoweb/tornado/security/advisories/GHSA-qppv-j76h-2rpx (vendor-advisory)
- www.vulncheck.com/advisories/tornado-before-6.3.3-http-request-smuggling-via-co… (third-party-advisory)
Frequently asked questions
- What is CVE-2023-54397?
- CVE-2023-54397 is a high-severity vulnerability in Tornadoweb Tornado, classified under Inconsistent Interpretation of HTTP Requests (HTTP Request/Response Smuggling). CVSS score: 7.5/10. Published 2026-09-15.
- How severe is CVE-2023-54397?
- High severity. CVSS v3 base score is 7.5 out of 10.