CVE-2026-79705
Description
A flaw was found in the buildah/copier Go package. When used outside of Buildah by a non-root caller, a crafted tar archive containing malicious symlinks can escape the target extraction directory and create files outside the intended destination. Buildah itself uses chroot hardening and is not affected.
Statement
This flaw allows a directory escape via crafted tar symlinks when a macOS Podman remote client performs podman cp against a malicious Podman system service server. Exploitation requires interaction with a malicious server and is not applicable to typical container deployments on Red Hat Enterprise Linux.
Mitigation
To mitigate this issue, users should ensure that `podman cp` operations are only performed against trusted Podman system service servers. Copying content from untrusted sources may expose the client to directory traversal vulnerabilities.
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 | 4.5 | N/A | 4.5 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | High | N/A | High |
| User Interaction | Required | N/A | Required |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | None | N/A | None |
| Integrity Impact | High | N/A | High |
| Availability Impact | None | N/A | None |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:N/I:H/A:N
cve.org: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:N/I:H/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.
Acknowledgements
Red Hat would like to thank Ibrahim Saglam, Junyi Liu, Oleh Konko, and Ron Masas for reporting this issue.
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