ETK-2026-175Zero's internal tracking ID, independent of the CVE number.
validatedZero produced an exploit or a check.description
Tornado applications using StaticFileHandler may expose files outside their static directory through symlinks that point elsewhere on the filesystem. An unauthenticated attacker can read files accessible to the service process if such a symlink already exists or the attacker can cause one to be created.
mitigation
Upgrade the tornado package to version 6.5.9. Until upgraded, remove symlinks that resolve outside static roots and prevent uploads or deployment processes from introducing them.
fixed in 6.5.9
outcome
Mechanism verified: the exploit fired on the vulnerable build and stayed silent on the patched one, but the server it ran against was ours, so no check ships for it.
source signals
Public signals that triggered or updated the pipeline. These are inputs for the deltas above.
- 2026-09-30 23:48Zghsa: trigger signal, started the run
- 2026-09-30 23:48Z
this entry in the feed
GET /api/v1/feed/ETK-2026-175
{ "etk_id": "ETK-2026-175", "cve_id": null, "display_id": "ETK-2026-175", "ghsa_id": "GHSA-c2m8-h5v5-343r", "euvd_id": null, "status": "published", "anchor_state": "awaiting_cve", "title": "Symlink traversal in Tornado StaticFileHandler", "summary": "Tornado applications using StaticFileHandler may expose files outside their static directory through symlinks that point elsewhere on the filesystem. An unauthenticated attacker can read files accessible to the service process if such a symlink already exists or the attacker can cause one to be created.", "mitigation": "Upgrade the tornado package to version 6.5.9. Until upgraded, remove symlinks that resolve outside static roots and prevent uploads or deployment processes from introducing them.", "vendor": "pip", "product": "pip:tornado", "affected": [ { "affected_notes": [], "affected_ranges": [ "<= 6.5.8" ], "ecosystem": "pip", "fixed_versions": [ "6.5.9" ], "package_name": "tornado", "purl": "pkg:pypi/tornado" } ], "cwes": null, "cvss_score": 8.2, "cvss_src": "cna_vendor", "cvss_vector": "CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N", "epss_score": null, "epss_percentile": null, "epss_asof": null, "automation": "contextual", "check": true, "check_confidence_basis": "mechanism_verified", "exploit": false, "pipeline_minutes": 14.34366385, "t0_at": null, "signals": { "check": { "at": "2026-10-01T00:40:25.033454+00:00", "days": -20.303733326435186, "is_lower_bound": true, "measured_at": "2026-10-21T07:57:47.615144+00:00", "url": null }, "public_poc": { "at": "2026-09-30T23:48:55+00:00", "days": -20.33949760252315, "is_lower_bound": true, "measured_at": "2026-10-21T07:57:47.615144+00:00", "url": "https://github.com/advisories/GHSA-c2m8-h5v5-343r" }, "trigger_signal": { "at": "2026-09-30T23:48:55+00:00", "days": -20.33949760252315, "is_lower_bound": true, "measured_at": "2026-10-21T07:57:47.615144+00:00", "url": "https://github.com/advisories/GHSA-c2m8-h5v5-343r" } } }
published 2026-10-01 00:26Z
last change 2026-10-21 07:48Z
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