CVE-2026-6429

netrc credential leak with reused proxy connection

View on CVE.org
Published May 13, 2026 CVSS 3.1 · 5.3 Medium EPSS < 1% KEV · Not listed
Description
When asked to both use a `.netrc` file for credentials and to follow HTTP
redirects, libcurl could leak the password used for the first host to the
followed-to host under certain circumstances.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Ubuntu USN Ubuntu USN USN-8227-1 curl vulnerabilities
History
Type Values Removed Values Added
Weaknesses CWE-200
Type Values Removed Values Added
First Time appeared Haxx
Haxx curl
Weaknesses NVD-CWE-noinfo
CPEs cpe:2.3:a:haxx:curl:*:*:*:*:*:*:*:*
Vendors & Products Haxx
Haxx curl
Type Values Removed Values Added
Metrics cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N'}

 ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N'}
Type Values Removed Values Added
Description A flaw was found in libcurl. When configured to use a .netrc file for credentials and follow HTTP redirects, libcurl can inadvertently send the password from the initial connection to the redirected host. This sensitive information disclosure occurs when both the original and redirect URLs use clear text HTTP, are performed over the same HTTP proxy, and the same connection is reused. This vulnerability, categorized as an Exposure of Sensitive Information to an Unauthorized Actor (CWE-200), could allow an attacker to obtain user credentials. When asked to both use a `.netrc` file for credentials and to follow HTTP redirects, libcurl could leak the password used for the first host to the followed-to host under certain circumstances.
Title curl: libcurl: Credential leak via reused proxy connection during HTTP redirects netrc credential leak with reused proxy connection
References
Type Values Removed Values Added
First Time appeared Curl
Curl libcurl
Vendors & Products Curl
Curl libcurl
Type Values Removed Values Added
Description A flaw was found in libcurl. When configured to use a .netrc file for credentials and follow HTTP redirects, libcurl can inadvertently send the password from the initial connection to the redirected host. This sensitive information disclosure occurs when both the original and redirect URLs use clear text HTTP, are performed over the same HTTP proxy, and the same connection is reused. This vulnerability, categorized as an Exposure of Sensitive Information to an Unauthorized Actor (CWE-200), could allow an attacker to obtain user credentials.
Title curl: libcurl: Credential leak via reused proxy connection during HTTP redirects
Weaknesses CWE-201
References
Metrics threat_severity

None

 cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N'}

threat_severity

Moderate
Earlier changes (1)
Weaknesses

Sources

Status
PUBLISHED
Assigner
curl
Published
Updated
Sep 15, 2026, 6:03 AM
Reserved
Apr 16, 2026, 2:48 PM

View source JSON

Updated
May 13, 2026, 2:03 PM

JSON

Status
Modified
Published
May 13, 2026, 1:01 PM
Modified
Nov 11, 2026, 8:10 PM

View source JSON

Severity
Moderate
Public date
Apr 29, 2026, 12:00 AM

View source Bugzilla JSON

Updated
Sep 21, 2026, 8:45 AM

JSON