Incorrect Resource Transfer Between Spheres Affecting tornado package, versions [,6.5.6)
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-PYTHON-TORNADO-17356107
- published17 Jun 2026
- disclosed15 Jun 2026
- creditYannick Wang
Introduced: 15 Jun 2026
CVE-2026-49853 (opens in a new tab)How to fix?
Upgrade tornado to version 6.5.6 or higher.
Overview
tornado is a Python web framework and asynchronous networking library, originally developed at FriendFeed.
Affected versions of this package are vulnerable to Incorrect Resource Transfer Between Spheres via SimpleAsyncHTTPClient. An attacker can obtain sensitive credentials by exploiting cross-origin redirects when the Authorization header is improperly forwarded to a different origin.
Note: This is only exploitable if follow_redirects is enabled and a redirect changes the scheme, host, or port of the URL. This is the default configuration.