PYSEC-2026-3387
See a problem?- Import Source
- https://github.com/pypa/advisory-database/blob/main/vulns/tornado/PYSEC-2026-3387.yaml
- JSON Data
- https://api.osv.dev/v1/vulns/PYSEC-2026-3387
- Aliases
- Published
- 2026-07-13T15:46:17.169568Z
- Modified
- 2026-07-13T16:32:47.094943597Z
- Severity
-
- 7.7 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N CVSS Calculator
- Summary
- Tornado: Authorization header forwarded across cross-origin redirects in SimpleAsyncHTTPClient
- Details
-
Summary
When SimpleAsyncHTTPClient follows a 3xx redirect, it shallow-copies the original HTTPRequest, rewrites the URL, decrements maxredirects, and removes only the Host header. It does not clear Authorization, authusername, authpassword, or authmode when the redirect target changes origin.
As a result, credentials intended for one origin can be forwarded to a different origin when follow_redirects=True, which is the default.
Beginning in Tornado 6.5.6,
SimpleAsyncHTTPClientmatches the default behavior oflibcurl(and thereforeCurlAsyncHTTPClient): When a redirect changes the scheme, host, or port of the url, theAuthorizationandCookieheaders will be removed when following the redirect. - References
Affected packages
PyPI / tornado
Package
- Name
- tornado
- View open source insights on deps.dev
- Purl
- pkg:pypi/tornado
Affected ranges
- Type
- ECOSYSTEM
- Events
-
Introduced0Unknown introduced version / All previous versions are affectedFixed6.5.6
Affected versions
0.*
0.2
1.*
1.0
1.1
1.1.1
1.2
1.2.1
2.*
2.0
2.1
2.1.1
2.2
2.2.1
2.3
2.4
2.4.1
3.*
3.0
3.0.1
3.0.2
3.1
3.1.1
3.2
3.2.1
3.2.2
4.*
4.0
4.0.1
4.0.2
4.1b2
4.1
4.2b1
4.2
4.2.1
4.3b1
4.3b2
4.3
4.4b1
4.4
4.4.1
4.4.2
4.4.3
4.5b1
4.5b2
4.5
4.5.1
4.5.2
4.5.3
5.*
5.0a1
5.0b1
5.0
5.0.1
5.0.2
5.1b1
5.1
5.1.1
6.*
6.0a1
6.0b1
6.0
6.0.1
6.0.2
6.0.3
6.0.4
6.1b1
6.1b2
6.1
6.2b1
6.2b2
6.2
6.3b1
6.3
6.3.1
6.3.2
6.3.3
6.4b1
6.4
6.4.1
6.4.2
6.5b1
6.5
6.5.1
6.5.2
6.5.3
6.5.4
6.5.5