CVE-2023-54397

HIGHPre-NVD 7.57.5—
EchelonGraph scoreHIGH confidence

Score 7.5 from GitHub Security Advisory (severity: CRITICAL) published 2026-09-15. a secondary CVSS source baseline 7.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 4 sources updated this week
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.5Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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.

CVSS v3
7.5
EG Score
7.5(high)
EG Risk
34(Track)
EG Risk 34/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity75% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
31%
KEV
Not listed

Published

September 15, 2026

Last Modified

September 17, 2026

Advisory Details (2)

Auto-updated Sep 15, 2026
Patch available. Sources: github.
generic

Tornado before 6.3.3 HTTP Request Smuggling via Content-Length | Advisories | VulnCheck

https://www.vulncheck.com/advisories/tornado-before-6.3.3-http-request-smuggling-via-content-length
github Patch Available

HTTP request smuggling via improper parsing of `Content-Length` fields and chunk lengths · Advisory · tornadoweb/tornado · GitHub

https://github.com/tornadoweb/tornado/security/advisories/GHSA-qppv-j76h-2rpx

Vendor Advisories for CVE-2023-54397(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(1 across 1 ecosystem)
PyPI(1)
PackageVulnerable rangeFixed inDependents
tornado0.2 ... 6.3b1 (69 versions)6.3.3—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 20× in last 7d / 20× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-09-19 02:29 UTCEG score recompute
  2. 2026-09-19 02:29 UTCGHSA enrichment
  3. 2026-09-18 19:26 UTCEPSS rescore
  4. 2026-09-18 14:46 UTCGHSA enrichment
  5. 2026-09-18 03:05 UTCEG score recompute
  6. 2026-09-18 03:05 UTCGHSA enrichment
  7. 2026-09-17 15:24 UTCEG score recompute
  8. 2026-09-17 15:24 UTCGHSA enrichment
  9. 2026-09-17 14:59 UTCEG score recompute
  10. 2026-09-17 14:59 UTCGHSA enrichment
  11. 2026-09-17 13:06 UTCGHSA enrichment
  12. 2026-09-17 01:25 UTCEG score recompute
  13. 2026-09-17 01:25 UTCGHSA enrichment
  14. 2026-09-16 14:06 UTCEPSS rescore
  15. 2026-09-16 13:44 UTCGHSA enrichment
  16. 2026-09-16 04:23 UTCEG score recompute
  17. 2026-09-16 04:23 UTCGHSA enrichment
  18. 2026-09-15 16:34 UTCEG score recompute
  19. 2026-09-15 15:24 UTCEG score recompute
  20. 2026-09-15 15:22 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2023-54397?
CVE-2023-54397 is a high vulnerability published on September 15, 2026. 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…
When was CVE-2023-54397 disclosed?
CVE-2023-54397 was first published in the National Vulnerability Database on September 15, 2026, with the most recent update on September 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2023-54397 actively exploited?
CVE-2023-54397 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 69.5% of all scored CVEs.
What is the CVSS score of CVE-2023-54397?
CVE-2023-54397 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2023-54397?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2023-54397, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2023-54397

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