Incorrect authorization in OpenSSH - CVE-2026-106586
Published: October 28, 2026
Vulnerability identifier: #VU158345
CSH Severity: Low
CVSS v4: 5.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-106586
CWE-ID: CWE-863
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to bypass authorized key restrictions on tunnel forwarding.
The vulnerability exists due to improper authorization in sshd when applying the authorized_keys restrict keyword to tunnel forwarding. A remote user can authenticate using a restricted key and request tunnel forwarding to establish a tunnel that the key restrictions should prohibit.
Exploitation requires tunnel forwarding to be enabled through PermitTunnel, which is disabled by default.
Affected software
OpenSSH
How to mitigate CVE-2026-106586
Install security update from vendor's website.
OpenSSH - update to 10.6p1