{"id":"CVE-2023-54397","title":"Tornado before 6.3.3 contains an HTTP request smuggling vulnerability due to improper parsing of Content-Length headers accepting non-standard characters","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 val…","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:H/A:N","cwe":["CWE-444"],"vendor":"tornadoweb","product":"tornado","affected":["tornado < 6.3.3"],"patched":["tornado 6.3.3"],"published":"2026-09-15","updated":"2026-09-17","sourceUpdated":"2026-09-17T15:16:39.103","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2023-54397","references":[{"url":"https://github.com/tornadoweb/tornado/security/advisories/GHSA-qppv-j76h-2rpx","label":"disclosure@vulncheck.com"},{"url":"https://www.vulncheck.com/advisories/tornado-before-6.3.3-http-request-smuggling-via-content-length","label":"disclosure@vulncheck.com"},{"url":"https://github.com/tornadoweb/tornado/commit/b7a5dd29bb02950303ae96055082c12a1ea0a4fe"},{"url":"https://github.com/tornadoweb/tornado"}],"tags":["nvd","cve.org","osv","pip"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-09-17T14:48:39.262559Z"},"epss":0.00367,"epssPercentile":0.30416,"aliases":["GHSA-qppv-j76h-2rpx"],"ecosystem":"pip","ingestedAt":"2026-09-15T15:39:12.928Z","slug":"CVE-2023-54397","body":"## Overview\n\nTornado 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Package advisory (CVE-2023-54397)\n\nAffected packages:\n\n- `tornado < 6.3.3`\n\nPatched in:\n\n- `tornado 6.3.3`\n\nSource: https://osv.dev/vulnerability/GHSA-qppv-j76h-2rpx","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}