CVE-2026-53803
Description
A symlink-following vulnerability in rsync allows local attackers to redirect predictable output paths to arbitrary filesystem locations. When rsync runs with elevated privileges (such as setuid or a privileged daemon), this enables arbitrary file overwrites and local privilege escalation.
Statement
This Important vulnerability in rsync allows a local attacker to achieve privilege escalation by exploiting a symlink following flaw. In Red Hat environments, the risk is elevated when rsync is configured to run with elevated privileges, such as setuid or in daemon mode, enabling an attacker to overwrite arbitrary files. The requirement for local access and specific privileged configurations prevents a Critical impact.
Mitigation
Do not run rsync setuid or point output paths (--log-file, --write-batch, or daemon config/log files) to user-writable directories like /tmp. While fs.protected_symlinks=1 prevents simple symlink creation in sticky directories on RHEL 7+, it does not stop parent-component attacks in standard directories. If the rsyncd daemon is unneeded, disable it (systemctl disable --now rsyncd); if required, enforce least-privilege execution and restrict network access to trusted 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).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7 | N/A | 7.8 |
| Attack Vector | Local | N/A | Local |
| Attack Complexity | High | N/A | Low |
| Privileges Required | Low | N/A | Low |
| 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:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
cve.org: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Confidentiality,Integrity,Access Control
Technical Impact: Read Files or Directories; Modify Files or Directories; Bypass Protection Mechanism
An attacker may be able to traverse the file system to unintended locations and read or overwrite the contents of unexpected files. If the files are used for a security mechanism then an attacker may be able to bypass the mechanism.
Other
Technical Impact: Execute Unauthorized Code or Commands
Windows simple shortcuts, sometimes referred to as soft links, can be exploited remotely since a ".LNK" file can be uploaded like a normal file. This can enable remote execution.
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