Vulnerability · Published Oct 1, 2026 · Assigned by VulnCheck
CVE-2026-103263Tornado before 6.5.9 StaticFileHandler Path Traversal via Symlink
Medium 5.9
In plain English
A medium-severity security flaw in tornado from tornadoweb. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 45% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | python-tornado | no fix listed | DEBIAN-CVE-2026-103263 |
| Debian:13 | python-tornado | no fix listed | DEBIAN-CVE-2026-103263 |
| Debian:14 | python-tornado | no fix listed | DEBIAN-CVE-2026-103263 |
| PyPI | tornado | 6.5.9 | GHSA-c2m8-h5v5-343r |
| Ubuntu:24.04:LTS | python-tornado | 6.4.0-1ubuntu0.6 | USN-8952-1 |
| Ubuntu:24.04:LTS | python-tornado | 6.4.0-1ubuntu0.7 | USN-8952-2 |
| Ubuntu:24.04:LTS | python-tornado | 6.4.0-1ubuntu0.7 | UBUNTU-CVE-2026-103263 |
| Ubuntu:26.04:LTS | python-tornado | 6.5.4-0.1ubuntu0.2 | USN-8952-1 |
| Ubuntu:26.04:LTS | python-tornado | 6.5.4-0.1ubuntu0.3 | UBUNTU-CVE-2026-103263 |
| Ubuntu:26.04:LTS | python-tornado | 6.5.4-0.1ubuntu0.3 | USN-8952-2 |
| Ubuntu:26.10 | python-tornado | 6.5.5-5ubuntu1.2 | USN-8952-2 |
| Ubuntu:26.10 | python-tornado | 6.5.5-5ubuntu1.1 | USN-8952-1 |
| Ubuntu:26.10 | python-tornado | 6.5.5-5ubuntu1.2 | UBUNTU-CVE-2026-103263 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| tornadoweb | tornado | 0 – before 6.5.9 |
Weakness: CWE-59 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N