Improper access control in OpenSSH - CVE-2026-73281
Published: September 3, 2026
Vulnerability identifier: #VU146881
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-2026-73281
CWE-ID: CWE-284
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to bypass intended local-only restrictions on agent operations.
The vulnerability exists due to improper access control in ssh-agent session binding handling when processing forwarded agent binding requests while the agent is locked. A remote user can send crafted requests through a forwarded agent to bypass intended local-only restrictions on agent operations.
This may permit adding PKCS#11 tokens and using keys with destination restrictions through a forwarded agent.
Affected software
OpenSSH
Ubuntu
openssh (Ubuntu package)
Ubuntu
openssh (Ubuntu package)
How to mitigate CVE-2026-73281
Install security update from vendor's website.
OpenSSH - update to 10.5p1
openssh (Ubuntu package) - addressed in versions 1:8.9p1-3ubuntu0.17, 1:9.6p1-3ubuntu13.19, 1:10.2p1-2ubuntu3.6
openssh (Ubuntu package) - addressed in versions 1:8.9p1-3ubuntu0.17, 1:9.6p1-3ubuntu13.19, 1:10.2p1-2ubuntu3.6