CVE-2026-53790
Description
A command injection vulnerability in rsync allows remote attackers to execute arbitrary commands by supplying shell metacharacters or newlines in unsanitized inputs, such as hostnames or hostspecs. This impacts multiple vectors—including the RSYNC_CONNECT_PROG variable, daemon hooks, rsync-ssl, and remote-shell parsing—executing commands with the privileges of the running process or user.
Statement
This Important vulnerability in rsync allows for remote command injection due to insufficient sanitization of user-supplied input across multiple code paths. While the attack complexity is high, successful exploitation could lead to arbitrary command execution under the privileges of the rsync process or the invoking user, impacting confidentiality, integrity, and availability. This risk is particularly relevant in environments where rsync is used for remote synchronization with untrusted sources or destinations.
Mitigation
Do not set RSYNC_CONNECT_PROG or pass untrusted hostnames/paths into rsync / rsync-ssl. If rsyncd is required, omit pre-xfer/post-xfer/early exec unless the command ignores client-controlled RSYNC_* values, and restrict TCP/873 to trusted clients
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).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 8.1 | N/A | 8.1 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | High | N/A | High |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | High |
| Integrity Impact | High | N/A | High |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
cve.org: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Confidentiality,Integrity,Availability,Non-Repudiation
Technical Impact: Execute Unauthorized Code or Commands; DoS: Crash, Exit, or Restart; Read Files or Directories; Modify Files or Directories; Read Application Data; Modify Application Data; Hide Activities
Attackers could execute unauthorized operating system commands, which could then be used to disable the product, or read and modify data for which the attacker does not have permissions to access directly. Since the targeted application is directly executing the commands instead of the attacker, any malicious activities may appear to come from the application or the application's owner.
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