CVE-2026-41568
Description
A flaw was found in the Moby container framework. A race condition during the docker cp mount setup allows a malicious container to create empty files or directories at arbitrary locations on the host filesystem. This vulnerability can lead to a denial of service by filling up disk space or interfering with critical system files.
Statement
This flaw is rated as Low impact. A race condition in the docker cp mount setup within the Moby container framework allows a malicious container to create empty files or directories at arbitrary locations on the host filesystem. Successful exploitation is difficult (AC:H) due to the timing-dependent nature of the race condition. Containers that do not have volume mounts are not affected, as the race occurs during volume bind-mount setup.
Denial of Service is possible by:
- Converting /etc/docker/daemon.json into a directory prevents the daemon from restarting
- Creating /etc/nologin prevents user logins
- Overwriting critical system paths with empty files can break host services
The container does not gain read or write access to existing host files — only the ability to create new empty files or directories at chosen paths.
Mitigation
Avoid using docker cp with untrusted running containers.
Recommended to apply patches: Mountpoint creation is now scoped to the container root using os.Root (Go 1.24+), which refuses to follow symlinks that escape the opened root directory. All filesystem operations in createIfNotExists (MkdirAll, OpenFile) are performed through the os.Root handle, so even if a symlink swap occurs after path resolution, the creation stays confined to the container root.
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 Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 3.9 | N/A | 6.1 |
| Attack Vector | Local | N/A | Local |
| Attack Complexity | High | N/A | High |
| Privileges Required | Low | N/A | Low |
| User Interaction | Required | N/A | Required |
| Scope | Changed | N/A | Changed |
| Confidentiality | None | N/A | None |
| Integrity Impact | Low | N/A | Low |
| Availability Impact | Low | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:C/C:N/I:L/A:L
cve.org: CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:C/C:N/I:L/A:H
Red Hat CVSS v3 Score Explanation
A:H->A:L: empty files only, difficult exploitation, systemd auto-restarts
Understanding the Weakness (CWE)
Integrity,Other
Technical Impact: Alter Execution Logic; Unexpected State
The attacker can gain access to otherwise unauthorized resources.
Integrity,Other
Technical Impact: Modify Application Data; Modify Files or Directories; Modify Memory; Other
Race conditions such as this kind may be employed to gain read or write access to resources which are not normally readable or writable by the user in question.
Integrity,Other
Technical Impact: Other
The resource in question, or other resources (through the corrupted one), may be changed in undesirable ways by a malicious user.
Non-Repudiation
Technical Impact: Hide Activities
If a file or other resource is written in this method, as opposed to in a valid way, logging of the activity may not occur.
Non-Repudiation,Other
Technical Impact: Other
In some cases it may be possible to delete files a malicious user might not otherwise have access to, such as log files.
Other
Technical Impact: Unexpected State
The product may perform invalid actions when the resource is in an unexpected state.
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