Tornado before 6.5.9 contains a path traversal vulnerability in StaticFileHandler that follows symbolic links inside the static root without confirming the resolved target stays within it. When a symlink pointing outside the static directory exists inside it, unauthenticated attackers can request it to read files such as configuration files, private keys, and application secrets accessible to the process user.
CVE-2026-103263
MEDIUMPre-NVD 5.95.9—Trending — 4 sources updated this weekElevated
EchelonGraph scoreHIGH confidence
Score 5.9 from GitHub Security Advisory (severity: HIGH) published 2026-10-01. A secondary CVSS source baseline 5.9; sources differ by 0.0.
Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
5.9EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
- Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.5%CVSS: 5.9Exploit: Elevated riskExposed services: Not assessed
A fix is available — apply it.
- CVSS v3
- 5.9
- EG Score
- 5.9MEDIUMhigh confidence
- EG Risk
- 43EG Risk 43/100CISA SSVC
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 computedSeverity59% × 45%Exploitation40% × 40%Automatability0% × 15%CISA SSVC: Track at low or medium mission impact; Track* at high (mission-essential systems).Action: A fix is available. Apply it within your standard update timelines. - EPSS PROB
- 0.5%
- EPSS %ILE
- 42nd
- KEV
- Not listed
CISA SSVCTrack at low or medium mission impact; Track* at high (mission-essential systems).
A fix is available. Apply it within your standard update timelines.
Exploitation public PoC (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table
Published
October 1, 2026
Last Modified
October 1, 2026
Advisory Details (3)
Auto-updated Oct 1, 2026🔬 Proof of concept available. Patch available. Sources: github, github_commit.
generic
Tornado before 6.5.9 StaticFileHandler Path Traversal via Symlink | Advisories | VulnCheck
https://www.vulncheck.com/advisories/tornado-before-6.5.9-staticfilehandler-path-traversal-via-symlinkgithub_commit
commit 437ab5f76565 (tornadoweb/tornado)
Fix landed in tornadoweb/tornado commit 437ab5f76565 — awaiting tagged release
https://github.com/tornadoweb/tornado/commit/437ab5f76565403b3403438d2e555d11f8128d32github Patch Available🟡 PoC Available
StaticFileHandler follows symlinks outside static root (path traversal) · Advisory · tornadoweb/tornado · GitHub
https://github.com/tornadoweb/tornado/security/advisories/GHSA-c2m8-h5v5-343rVendor Advisories for CVE-2026-103263(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)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| tornado | 0.2 ... 6.5b1 (84 versions) | 6.5.9 | — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 12× in last 7d / 12× 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.
- 2026-10-03 22:06 UTCEG score recompute
- 2026-10-03 22:06 UTCGHSA enrichment
- 2026-10-03 14:25 UTCEPSS rescore
- 2026-10-02 21:17 UTCEG score recompute
- 2026-10-02 21:17 UTCGHSA enrichment
- 2026-10-01 20:29 UTCEG score recompute
- 2026-10-01 20:29 UTCGHSA enrichment
- 2026-10-01 19:31 UTCEG score recompute
- 2026-10-01 19:31 UTCGHSA enrichment
- 2026-10-01 11:27 UTCEG score recompute
- 2026-10-01 10:51 UTCEG score recompute
- 2026-10-01 10:50 UTCMITRE cvelistV5first tracked
Related CVEs(same CWE)
Frequently asked(5)
What is CVE-2026-103263?
CVE-2026-103263 is a medium vulnerability published on October 1, 2026. Tornado before 6.5.9 contains a path traversal vulnerability in StaticFileHandler that follows symbolic links inside the static root without confirming the resolved target stays within it. When a symlink pointing outside the static directory exists inside it, unauthenticated attackers can request…
When was CVE-2026-103263 disclosed?
CVE-2026-103263 was first published on October 1, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-103263 actively exploited?
CVE-2026-103263 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.5% probability of exploitation in the next 30 days (42nd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-103263?
CVE-2026-103263 has a CVSS base score of 5.9 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-103263?
A fix for CVE-2026-103263 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-103263 are linked in the Vendor Advisories panel on this page.
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-103263
Is Your Infrastructure Affected by CVE-2026-103263?
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