CVE-2026-0964
Description
A malicious SCP server can send unexpected paths that could make the client application override local files outside of working directory. This could be misused to create malicious executable or configuration files and make the user execute them under specific consequences.
This is the same issue as in OpenSSH, tracked as CVE-2019-6111.
Mitigation
Do not use SCP! SCP is deprecated for several years and will
be removed in future releases!
If you have to, the application MUST validate the path returned
from `ssh_scp_request_get_filename()` is the path the application
requested. The libssh does not do any writing in this case.
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 | 5 | 6.3 | 5 |
| Attack Vector | Network | Network | Network |
| Attack Complexity | High | Low | High |
| Privileges Required | None | None | None |
| User Interaction | Required | Required | Required |
| Scope | Unchanged | Unchanged | Unchanged |
| Confidentiality | Low | Low | Low |
| Integrity Impact | Low | Low | Low |
| Availability Impact | Low | Low | Low |
Vector
Red Hat: CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:L
NVD: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L
cve.org: CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:L
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 CTyun (Red-Shield Security Lab) and Jakub Jelen (libssh) for reporting this issue.
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