CVE-2026-59999 Security feature bypass in OpenSSH

What is CVE-2026-59999?

CVE-2026-59999 is a medium-severity vulnerability in OpenSSH, published on 8 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

In sshd in OpenSSH before 10.4, DisableForwarding=yes was supposed to take precedence over PermitTunnel=yes, but did not.

Weakness: CWE-348

Which versions are affected by CVE-2026-59999?

It affects 1 product.

Products include OpenSSH.

How do I fix CVE-2026-59999?

Upgrade to a fixed version.

Is CVE-2026-59999 being exploited?

There is no known exploitation of CVE-2026-59999 in the wild and no public exploit code.

Other vulnerabilities in OpenSSH

• CVE-2003-0786 Auth bypass in n/a Critical 10.0
• CVE-2003-0693 Memory corruption in n/a Critical 10.0
• CVE-2002-0640 Memory corruption in n/a Critical 10.0
• CVE-2001-0144 Integer overflow in n/a Critical 10.0
• CVE-2000-0999 Memory corruption in n/a Critical 10.0

All OpenSSH vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as ALPINE-CVE-2026-59999, AZL-92051, BELL-CVE-2026-59999, CLSA-2026-1785317563, DEBIAN-CVE-2026-59999, ECHO-eb7c-7431-a44d and 5 more.