benoitc hackney up to 4.0.0 src/hackney_h3.erl redirect

Summaryinfo

A vulnerability identified as problematic has been detected in benoitc hackney up to 4.0.0. This affects an unknown part of the file src/hackney_h3.erl. This manipulation causes redirect. This vulnerability is handled as CVE-2026-47070. The attack can be initiated remotely. There is not any exploit available. You should upgrade the affected component.

Detailsinfo

A vulnerability has been found in benoitc hackney up to 4.0.0 and classified as problematic. Affected by this vulnerability is some unknown functionality of the file src/hackney_h3.erl. The manipulation with an unknown input leads to a redirect vulnerability. The CWE definition for the vulnerability is CWE-601. A web application accepts a user-controlled input that specifies a link to an external site, and uses that link in a Redirect. This simplifies phishing attacks. As an impact it is known to affect integrity. The summary by CVE is:

Sensitive Data Exposure vulnerability in benoitc hackney allows Retrieve Embedded Sensitive Data. The HTTP/3 redirect handler in src/hackney_h3.erl passes the original request headers unchanged to the redirect target without performing any cross-origin check. When a client issues an HTTP/3 request with follow_redirect enabled and includes Authorization or Cookie headers, a server responding with a 3xx redirect to a different host will cause the client to forward those credentials verbatim to the new origin. The main hackney.erl module has maybe_strip_auth_on_redirect/2 (guarded by the location_trusted option) to address CVE-2018-1000007, but hackney_h3.erl is missing this protection entirely. This issue affects hackney: from 3.1.1 before 4.0.1.

The weakness was released by Peter Ullrich and Jonatan Männchen. The advisory is shared at github.com. This vulnerability is known as CVE-2026-47070 since 05/18/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. It demands that the victim is doing some kind of user interaction. Technical details are known, but no exploit is available. MITRE ATT&CK project uses the attack technique T1204.001 for this issue.

Upgrading to version 4.0.1 eliminates this vulnerability. Applying the patch c58d5b50bade146360b85caf3dc8065807b08246 is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-31692). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Vendor

• benoitc

Name

• hackney

Version

• 4.0

Website

• Product: https://github.com/benoitc/hackney/

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Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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