CVE-2026-53793
Description
A flaw was found in rsync. This vulnerability allows remote clients to bypass path confinement, a security measure designed to restrict file access. By crafting specific paths that include a '/./' boundary marker within a chroot environment, an attacker can gain unauthorized read or write access to files outside the intended module's directory. This could lead to sensitive information disclosure or data manipulation.
Statement
This Important rsync flaw enables remote clients to bypass path confinement when the daemon operates in chroot mode with a module root containing a /./ boundary marker. Successful exploitation could lead to unauthorized read and write access to files outside the intended chroot environment, though the attack complexity is high.
Mitigation
To mitigate this issue, avoid configuring rsync modules with a /./ boundary marker in their root path when operating in chroot mode. Review existing rsync configurations to ensure that module root paths do not contain /./ when chroot is enabled. If chroot mode is not strictly required for a given rsync module, consider disabling it. If changes are made to the rsync configuration, a restart of the rsync service may be required for the changes to take effect.
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 | 7.4 | N/A | 7.4 |
| 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 | None | N/A | None |
Vector
Red Hat: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
cve.org: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
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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