CVE-2026-49853

HIGH 7.7

Tornado: Authorization header forwarded across cross-origin redirects in SimpleAsyncHTTPClient

CVSS Score

7.7

EPSS Score

0.0%

EPSS Percentile

0th

Tornado is a Python web framework and asynchronous networking library. Prior to 6.5.6, SimpleAsyncHTTPClient shallow-copied redirected requests and removed only the Host header, leaving Authorization, auth_username, auth_password, and auth_mode in place when a redirect changed scheme, host, or port. This issue is fixed in version 6.5.6.

CWE	CWE-200
Vendor	tornadoweb
Product	tornado
Published	Jul 14, 2026

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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Changed

Confidentiality

High

Integrity

None

Availability

None

Affected Versions

tornadoweb / tornado

< 6.5.6

References

NVD ↗ CVE.org ↗ EPSS Data ↗

github.com: https://github.com/tornadoweb/tornado/security/advisories/GHSA-3x9g-8vmp-wqvf github.com: https://github.com/tornadoweb/tornado/pull/3626 github.com: https://github.com/tornadoweb/tornado/commit/aba2569f7ed7a6bdbef816658fb6b7182531b751 github.com: https://github.com/tornadoweb/tornado/releases/tag/v6.5.6