CVE-2026-6429
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.
Statement
Moderate: A flaw in libcurl could lead to credential leakage. This issue occurs when libcurl is configured to use a .netrc file for credentials and follows HTTP redirects, potentially exposing passwords to the redirected host. Exploitation requires both the original and redirect URLs to be clear text HTTP, performed over the same HTTP proxy, and with connection reuse. The curl command-line tool is not affected by this vulnerability.
Mitigation
To prevent the credential leak, avoid using the combination of .netrc for credentials, clear text HTTP URLs, and an HTTP proxy when making requests with libcurl. This operational control prevents the specific conditions that enable the vulnerability.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 6.5 | N/A | 5.3 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | High |
| Privileges Required | None | N/A | Low |
| User Interaction | Required | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | High |
| Integrity Impact | None | N/A | None |
| Availability Impact | None | N/A | None |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
cve.org: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Files or Directories; Read Memory; Read Application Data
Sensitive data may be exposed to attackers.
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