CVE-2026-53801

Description

A symlink race condition in rsync's sender directory scanning logic allows a local attacker to bypass intended access restrictions. By replacing a symlink with a directory entry pointing outside the module root during an active scan, the attacker can force rsync to enumerate and transfer unauthorized files, resulting in directory traversal and information disclosure.

Statement

A Moderate severity information disclosure vulnerability in rsync's sender-side directory scanning logic allows an attacker to read files outside the intended synchronization root. To exploit this flaw, the attacker must have write access to the rsync source directories in order to create or manipulate symlinks.

Mitigation

To mitigate this issue, ensure that rsync source directories have restricted write permissions. Untrusted users should not have the ability to create or manipulate symlinks within the paths scanned by rsync, whether operating in daemon mode or non-daemon sender-side scanning. Implementing strict access controls on these directories can prevent the preconditions necessary for exploitation.

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 HatNVDcve.org
Base Score5.9N/A5.9
Attack VectorNetworkN/ANetwork
Attack ComplexityHighN/AHigh
Privileges RequiredNoneN/ANone
User InteractionNoneN/ANone
ScopeUnchangedN/AUnchanged
ConfidentialityHighN/AHigh
Integrity ImpactNoneN/ANone
Availability ImpactNoneN/ANone

Vector

Red Hat: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

cve.org: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

Understanding the Weakness (CWE)

Integrity,Confidentiality,Availability

Technical Impact: Execute Unauthorized Code or Commands

The attacker may be able to create or overwrite critical files that are used to execute code, such as programs or libraries.

Integrity

Technical Impact: Modify Files or Directories

The attacker may be able to overwrite or create critical files, such as programs, libraries, or important data. If the targeted file is used for a security mechanism, then the attacker may be able to bypass that mechanism. For example, appending a new account at the end of a password file may allow an attacker to bypass authentication.

Confidentiality

Technical Impact: Read Files or Directories

The attacker may be able read the contents of unexpected files and expose sensitive data. If the targeted file is used for a security mechanism, then the attacker may be able to bypass that mechanism. For example, by reading a password file, the attacker could conduct brute force password guessing attacks in order to break into an account on the system.

Availability

Technical Impact: DoS: Crash, Exit, or Restart

The attacker may be able to overwrite, delete, or corrupt unexpected critical files such as programs, libraries, or important data. This may prevent the product from working at all and in the case of protection mechanisms such as authentication, it has the potential to lock out product users.

Frequently Asked Questions

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