CVE-2026-3783

Plain English Summary

AI-powered analysis for quick understanding

This vulnerability allows an attacker to potentially capture an OAuth2 bearer token when a user is redirected from one website to another, exposing sensitive information. This can happen if the second website has credentials stored in the user's .netrc file, which curl mistakenly sends along with the token.

Technical Description

When an OAuth2 bearer token is used for an HTTP(S) transfer, and that transfer performs a redirect to a second URL, curl could leak that token to the second hostname under some circumstances. If the hostname that the first request is redirected to has information in the used .netrc file, with either of the `machine` or `default` keywords, curl would pass on the bearer token set for the first host also to the second one.

CVSS Vector Analysis

Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredNone
User InteractionNone
Confidentiality ImpactLow
Integrity ImpactNone
Availability ImpactNone
ScopeUnchanged

Vector String

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

Exploit Resources

Search for proof-of-concept code and exploit modules

Official References

Est. Bounty
$724($500-$1K)
Vendor Response
Grade APatched in 1 day

Quick Information

Published

Mar 11, 2026

27 days ago

Last Modified

Mar 12, 2026

26 days ago

Vendor

haxx

Product

curl

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CVE-2026-3784Medium

This vulnerability allows an attacker to potentially gain access to sensitive information by reusing an existing HTTP proxy connection, even if the new request uses different login credentials. This issue occurs when the curl tool fails to establish a separate connection for requests that require different authentication, which could lead to unauthorized data exposure if an attacker can control the proxy or its traffic.

CVE-2026-1965Medium

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