CVE-2026-59846: Shell Metacharacter Injection via %r ProxyCommand in libssh
CVE-2026-59846 Published on July 21, 2026

Libssh: libssh: information disclosure via proxycommand %r username expansion
A flaw was found in libssh. A malicious username expanded through %r in ProxyCommand handling can inject shell metacharacters, exposing environment variables and causing unintended shell behavior.

NVD

Vulnerability Analysis

CVE-2026-59846 is exploitable with local system access, requires user interaction and a small amount of user privileges. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have a small impact on confidentiality and integrity, and no impact on availability.

Attack Vector:
LOCAL
Attack Complexity:
LOW
Privileges Required:
LOW
User Interaction:
REQUIRED
Scope:
UNCHANGED
Confidentiality Impact:
LOW
Integrity Impact:
LOW
Availability Impact:
NONE

Timeline

Reported to Red Hat.

Made public. 83 days later.


Products Associated with CVE-2026-59846

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Red Hat Enterprise Linux (RHEL)
 
Red Hat Hummingbird
 

Affected Versions

Red Hat Enterprise Linux 10: Red Hat Enterprise Linux 8: Red Hat Enterprise Linux 9: Red Hat Hardened Images: