CVE-2026-49853 (High) detected in tornado-5.1.1.tar.gz

[mend-bolt-for-github]

CVE-2026-49853 - High Severity Vulnerability

Vulnerable Library - tornado-5.1.1.tar.gz

Tornado is a Python web framework and asynchronous networking library, originally developed at FriendFeed.

Library home page: https://files.pythonhosted.org/packages/e6/78/6e7b5af12c12bdf38ca9bfe863fcaf53dc10430a312d0324e76c1e5ca426/tornado-5.1.1.tar.gz

Path to dependency file: /tmp/ws-ua_20220122232947_MZFNWS/archiveExtraction_KXRZMM/PZSZKX/20220122232947/codechung_depth_0/awscli-bundle/packages/urllib3-1.25.10.tar/urllib3-1.25.10/dev-requirements.txt

Path to vulnerable library: /awscli-bundle/packages/urllib3-1.25.10.tar/urllib3-1.25.10/dev-requirements.txt,/awscli-bundle/awscli-bundle/packages/urllib3-1.25.7.tar/urllib3-1.25.7/dev-requirements.txt,/awscli-bundle/awscli-bundle/packages/urllib3-1.25.10.tar/urllib3-1.25.10/dev-requirements.txt,/awscli-bundle/awscli-bundle/packages/urllib3-1.25.7.tar/urllib3-1.25.7/docs/requirements.txt,/awscli-bundle/packages/urllib3-1.25.10.tar/urllib3-1.25.10/docs/requirements.txt,/awscli-bundle/packages/urllib3-1.25.7.tar/urllib3-1.25.7/docs/requirements.txt,/awscli-bundle/awscli-bundle/packages/urllib3-1.25.10.tar/urllib3-1.25.10/docs/requirements.txt,/awscli-bundle/packages/urllib3-1.25.7.tar/urllib3-1.25.7/dev-requirements.txt

Dependency Hierarchy:

• ❌ tornado-5.1.1.tar.gz (Vulnerable Library)

Found in HEAD commit: de1c2b0d1a23367b161c2d995029f9693bd8a155

Found in base branch: master

Vulnerability Details

Summary When SimpleAsyncHTTPClient follows a 3xx redirect, it shallow-copies the original HTTPRequest, rewrites the URL, decrements max_redirects, and removes only the Host header. It does not clear Authorization, auth_username, auth_password, or auth_mode 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, "SimpleAsyncHTTPClient" matches the default behavior of "libcurl" (and therefore "CurlAsyncHTTPClient"): When a redirect changes the scheme, host, or port of the url, the "Authorization" and "Cookie" headers will be removed when following the redirect.

Publish Date: 2026-06-15

URL: CVE-2026-49853

CVSS 3 Score Details (7.7)

Base Score Metrics:

• Exploitability Metrics:
  • Attack Vector: Network
  • Attack Complexity: Low
  • Privileges Required: Low
  • User Interaction: None
  • Scope: Changed
• Impact Metrics:
  • Confidentiality Impact: High
  • Integrity Impact: None
  • Availability Impact: None

For more information on CVSS3 Scores, click here.

Suggested Fix

Type: Upgrade version

Origin: GHSA-3x9g-8vmp-wqvf

Release Date: 2026-06-15

Fix Resolution: 6.5.6

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