---
id: CVE-2026-3783
title: |-
  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 re…
summary: |-
  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 re…
severity: medium
cvss: 5.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N'
cwe:
  - CWE-522
  - CWE-201
vendor: haxx
product: curl
affected:
  - 'curl >= 7.33.0, < 8.19.0'
patched:
  - curl 8.19.0
published: '2026-03-11'
updated: '2026-09-15'
sourceUpdated: '2026-09-15T07:16:27.720'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-3783'
references:
  - url: 'https://curl.se/docs/CVE-2026-3783.html'
    label: 2499f714-1537-4658-8207-48ae4bb9eae9
  - url: 'https://curl.se/docs/CVE-2026-3783.json'
    label: 2499f714-1537-4658-8207-48ae4bb9eae9
  - url: 'https://hackerone.com/reports/3583983'
    label: 2499f714-1537-4658-8207-48ae4bb9eae9
  - url: 'http://www.openwall.com/lists/oss-security/2026/03/11/2'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-3783.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-3783'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2446450'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-3783'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-3783'
  - url: 'https://access.redhat.com/errata/RHSA-2026:55450'
  - url: 'https://access.redhat.com/errata/RHSA-2026:55439'
  - url: 'https://access.redhat.com/errata/RHSA-2026:63140'
  - url: 'https://access.redhat.com/errata/RHSA-2026:63135'
  - url: 'https://access.redhat.com/errata/RHSA-2026:63138'
  - url: 'https://access.redhat.com/errata/RHSA-2026:61783'
  - url: 'https://access.redhat.com/errata/RHSA-2026:6893'
  - url: 'https://access.redhat.com/errata/RHSA-2026:66018'
  - url: 'https://access.redhat.com/errata/RHSA-2026:58981'
tags:
  - nvd
  - cve.org
  - exploit-available
  - csaf
  - vex
  - red-hat
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-03-11T14:25:28.836990Z'
epss: 0.00454
epssPercentile: 0.38666
ingestedAt: '2026-09-15T07:33:29.262Z'
scores:
  nvd: 5.3
  vendor: 5.7
---

## Overview

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.

## Affected

- `curl >= 7.33.0, < 8.19.0`

## Remediation

Upgrade past the affected range:

- `curl 8.19.0`

## Vendor advisories

- **RHSA-2026:55450** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux BaseOS (v. 10) · released 2026-08-17 · [advisory](https://access.redhat.com/errata/RHSA-2026:55450)
- **RHSA-2026:55439** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 9), Red Hat Enterprise Linux BaseOS (v. 9) · released 2026-08-17 · [advisory](https://access.redhat.com/errata/RHSA-2026:55439)
- **RHSA-2026:63140** · Red Hat · fixed in: Cert Manager support for Red Hat OpenShift release 1.19 · released 2026-09-03 · [advisory](https://access.redhat.com/errata/RHSA-2026:63140)
- **RHSA-2026:63135** · Red Hat · fixed in: Cert Manager support for Red Hat OpenShift release 1.19 · released 2026-09-03 · [advisory](https://access.redhat.com/errata/RHSA-2026:63135)
- **RHSA-2026:63138** · Red Hat · fixed in: Cert Manager support for Red Hat OpenShift release 1.19 · released 2026-09-03 · [advisory](https://access.redhat.com/errata/RHSA-2026:63138)
- **RHSA-2026:61783** · Red Hat · fixed in: Red Hat Discovery 2 · released 2026-08-31 · [advisory](https://access.redhat.com/errata/RHSA-2026:61783)
- **RHSA-2026:6893** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-04-07 · [advisory](https://access.redhat.com/errata/RHSA-2026:6893)
- **RHSA-2026:66018** · Red Hat · fixed in: Red Hat Update Infrastructure 5 · released 2026-09-09 · [advisory](https://access.redhat.com/errata/RHSA-2026:66018)
- **RHSA-2026:58981** · Red Hat · fixed in: Red Hat Update Infrastructure 5 · released 2026-08-24 · [advisory](https://access.redhat.com/errata/RHSA-2026:58981)
- **Red Hat VEX** · Moderate · affected: Confidential Compute Attestation, Logging Subsystem for Red Hat OpenShift, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, … · no fix planned: Confidential Compute Attestation, Logging Subsystem for Red Hat OpenShift, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, … · updated 2026-09-18 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-3783.json)