CVE-2026-7168
Description
A flaw was found in libcurl. When a user performs a transfer over an HTTP proxy using Digest authentication and then reuses the same handle for a second transfer with a different proxy host, libcurl incorrectly sends the Proxy-Authorization header intended for the first proxy to the second proxy. This could lead to the disclosure of sensitive authentication information to an unintended proxy, potentially allowing an attacker to gain unauthorized access or impersonate the user.
Statement
Moderate: A flaw in libcurl allows for information disclosure when a client reuses a handle for HTTP proxy transfers. If a libcurl application uses Digest authentication with one proxy and then connects to a different proxy using the same handle, the Proxy-Authorization header from the initial connection may be inadvertently sent to the second proxy, potentially exposing sensitive authentication data.
Mitigation
To mitigate this issue, applications using libcurl should avoid reusing handles when switching between different HTTP proxies, especially after performing Digest authentication. This operational control prevents the unintended disclosure of `Proxy-Authorization` headers to subsequent proxy hosts.
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 | 5.3 | 5.3 | 5.3 |
| Attack Vector | Network | Network | Network |
| Attack Complexity | Low | Low | Low |
| Privileges Required | None | None | None |
| User Interaction | None | None | None |
| Scope | Unchanged | Unchanged | Unchanged |
| Confidentiality | Low | Low | Low |
| Integrity Impact | None | None | None |
| Availability Impact | None | None | None |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
NVD: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/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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