CVE-2026-92390

Description

A flaw was found in curl. When the command-line tool is executed with the remote header name option to prevent overwriting existing files, a malicious server can bypass this protection by returning an intermediate HTTP 103 (Early Hints) response or through specific header ordering. This flaw allows an attacker controlling a remote server to overwrite existing local files on the client system.

Statement

This vulnerability is rated as Low severity because it is confined to the curl command-line utility, leaves the underlying libcurl library unaffected, and requires explicit use of non-default command arguments against an untrusted remote server. In typical Red Hat enterprise deployments, core services and applications integrate with libcurl for HTTP transfers rather than invoking the standalone CLI, significantly limiting exposure. Exploitation depends on user interaction where an administrator or script actively downloads files using the remote header naming option while handling specific server response codes like 103 Early Hints.

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 HatNVDcve.org
Base Score6.5N/A7.5
Attack VectorNetworkN/ANetwork
Attack ComplexityLowN/ALow
Privileges RequiredNoneN/ANone
User InteractionRequiredN/ANone
ScopeUnchangedN/AUnchanged
ConfidentialityNoneN/ANone
Integrity ImpactHighN/AHigh
Availability ImpactNoneN/ANone

Vector

Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/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)

Integrity,Confidentiality

Technical Impact: Read Files or Directories

The application can operate on unexpected files, such as system files or configuration files. Confidentiality is violated when the targeted filename is not directly readable by the attacker.

Integrity,Confidentiality,Availability

Technical Impact: Modify Files or Directories; Execute Unauthorized Code or Commands

The application can operate on unexpected files. This may violate integrity if the filename is written to, or if the filename is for a program or other form of executable code.

Availability

Technical Impact: DoS: Crash, Exit, or Restart; DoS: Resource Consumption (Other)

The application can operate on unexpected files. Availability can be violated if the attacker specifies an unexpected file that the application modifies. Availability can also be affected if the attacker specifies a filename for a large file, or points to a special device or a file that does not have the format that the application expects.

Acknowledgements

Red Hat would like to thank Joshua Rogers (Aisle Research) for reporting this issue.

Frequently Asked Questions

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