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CVE-2026-49853
Tornado: Authorization header forwarded across cross-origin redirects in SimpleAsyncHTTPClient
High7.7EPSS 0.45%
- Published
- Updated
- Reserved
- Assigned by
- GitHub_M
Description
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.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | High7.7 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N |
| NVDNVD · Deferred | 3.1 | High7.7 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N |
- EPSS (exploitation in 30 days)
- 0.45% · top 61% of all CVEs (6 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
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The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.7.
Weakness
Affected products
- affected < 6.5.6
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- PyPItornadoGHSA-3x9g-8vmp-wqvf (opens in a new tab)
References (4)
- https://github.com/tornadoweb/tornado/security/advisories/GHSA-3x9g-8vmp-wqvf (opens in a new tab)x_refsource_CONFIRM
- https://github.com/tornadoweb/tornado/pull/3626 (opens in a new tab)x_refsource_MISC
- https://github.com/tornadoweb/tornado/commit/aba2569f7ed7a6bdbef816658fb6b7182531b751 (opens in a new tab)x_refsource_MISC
- https://github.com/tornadoweb/tornado/releases/tag/v6.5.6 (opens in a new tab)x_refsource_MISC
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-3x9g-8vmp-wqvf (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-49853)Record last updated .