CVE-2026-12064
Description
A flaw was found in curl. When a user invokes curl with a schemeless URL and specifies SFTP (SSH File Transfer Protocol) or SCP (Secure Copy Protocol) as the default protocol, the tool layer fails to initialize critical SSH security options. This bypasses host verification, allowing curl to connect to an unverified SSH remote host without alerting the user. This could enable an attacker to intercept or manipulate data through a man-in-the-middle attack.
Statement
This Important flaw in curl allows an attacker to bypass SSH host verification when a user invokes curl with a schemeless URL and specifies SFTP or SCP as the default protocol. This can lead to man-in-the-middle attacks, enabling data interception or manipulation without user awareness in Red Hat environments.
Mitigation
To mitigate this issue, avoid using the `--proto-default sftp` or `--proto-default scp` options with schemeless URLs when invoking the `curl` command. Instead, explicitly specify the protocol in the URL (e.g., `sftp://host/path` or `scp://host/path`).
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 | 7.5 | N/A | 7.5 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | None | N/A | None |
| Integrity Impact | High | N/A | High |
| Availability Impact | None | N/A | None |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Understanding the Weakness (CWE)
Access Control
Technical Impact: Bypass Protection Mechanism
Frequently Asked Questions
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