Red Hat Security Advisory: openssh security update
🔗 CVE IDs covered (5)
📋 Description
CVE-2026-59997 — openssh: OpenSSH: SFTP security bypass due to command-line argument parsing flaw CVE-2026-59998 — openssh: OpenSSH: Undocumented GSSAPIStrictAcceptorCheck behavior impacts security in Windows Active Directory CVE-2026-60000 — openssh: OpenSSH: Denial of Service via excessive GSSAPI authentication attempts CVE-2026-60001 — openssh: OpenSSH: Brute-force attacks facilitated due to insufficient authentication delay CVE-2026-73283 — openssh: OpenSSH: Tunnel forwarding restriction bypass
🎯 Affected products107
- Red Hat Enterprise Linux AppStream (v. 8)
- Red Hat Enterprise Linux BaseOS (v. 8)
- openssh-0:8.0p1-34.el8_10.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
- openssh-0:8.0p1-34.el8_10.ppc64le as a component of Red Hat Enterprise Linux BaseOS (v. 8)
- openssh-0:8.0p1-34.el8_10.s390x as a component of Red Hat Enterprise Linux BaseOS (v. 8)
- openssh-0:8.0p1-34.el8_10.src as a component of Red Hat Enterprise Linux BaseOS (v. 8)
- openssh-0:8.0p1-34.el8_10.x86_64 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
- openssh-askpass-0:8.0p1-34.el8_10.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 8)
- openssh-askpass-0:8.0p1-34.el8_10.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 8)
- openssh-askpass-0:8.0p1-34.el8_10.s390x as a component of Red Hat Enterprise Linux AppStream (v. 8)
- openssh-askpass-0:8.0p1-34.el8_10.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 8)
- openssh-askpass-debuginfo-0:8.0p1-34.el8_10.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 8)
- openssh-askpass-debuginfo-0:8.0p1-34.el8_10.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
- openssh-askpass-debuginfo-0:8.0p1-34.el8_10.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 8)
- openssh-askpass-debuginfo-0:8.0p1-34.el8_10.ppc64le as a component of Red Hat Enterprise Linux BaseOS (v. 8)
- openssh-askpass-debuginfo-0:8.0p1-34.el8_10.s390x as a component of Red Hat Enterprise Linux AppStream (v. 8)
- openssh-askpass-debuginfo-0:8.0p1-34.el8_10.s390x as a component of Red Hat Enterprise Linux BaseOS (v. 8)
- openssh-askpass-debuginfo-0:8.0p1-34.el8_10.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 8)
- openssh-askpass-debuginfo-0:8.0p1-34.el8_10.x86_64 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
- openssh-cavs-0:8.0p1-34.el8_10.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
- openssh-cavs-0:8.0p1-34.el8_10.ppc64le as a component of Red Hat Enterprise Linux BaseOS (v. 8)
- openssh-cavs-0:8.0p1-34.el8_10.s390x as a component of Red Hat Enterprise Linux BaseOS (v. 8)
- openssh-cavs-0:8.0p1-34.el8_10.x86_64 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
- openssh-cavs-debuginfo-0:8.0p1-34.el8_10.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 8)
- openssh-cavs-debuginfo-0:8.0p1-34.el8_10.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
- openssh-cavs-debuginfo-0:8.0p1-34.el8_10.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 8)
- openssh-cavs-debuginfo-0:8.0p1-34.el8_10.ppc64le as a component of Red Hat Enterprise Linux BaseOS (v. 8)
- openssh-cavs-debuginfo-0:8.0p1-34.el8_10.s390x as a component of Red Hat Enterprise Linux AppStream (v. 8)
- openssh-cavs-debuginfo-0:8.0p1-34.el8_10.s390x as a component of Red Hat Enterprise Linux BaseOS (v. 8)
- openssh-cavs-debuginfo-0:8.0p1-34.el8_10.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 8)
- +77 more not shown
✅ Remediation
For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 Workaround: To mitigate this issue, ensure that all security-relevant command-line arguments for the `internal-sftp` server are positioned within the first nine arguments. Alternatively, consider using the default SFTP server implementation if custom configurations relying on numerous arguments are not strictly necessary. If `internal-sftp` is used with more than nine arguments, verify that no critical security options are being silently discarded. Workaround: To mitigate this issue, avoid using GSSAPI authentication for `sshd` when the server is integrated with a Windows Active Directory environment. If GSSAPI authentication is not strictly required, it can be disabled by setting `GSSAPIAuthentication no` in the `/etc/ssh/sshd_config` file. After modifying the configuration, the `sshd` service must be restarted for the changes to take effect. Note that restarting the `sshd` service will terminate all active SSH sessions. ```bash # echo "GSSAPIAuthentication no" >> /etc/ssh/sshd_config # systemctl restart sshd ``` Alternatively, if GSSAPI authentication is necessary in such an environment, ensure that the network path between the client and the `sshd` server, and to the Active Directory, is secured and trusted to prevent man-in-the-middle attacks. Workaround: Set PermitTunnel no in /etc/ssh/sshd_config to disable TUN/TAP tunnel forwarding server-wide. Alternatively, restrict tunnel permissions for specific users or groups using Match blocks in sshd_config or explicit no-tun directives in authorized_keys.
🔗 References (8)
- selfhttps://access.redhat.com/errata/RHSA-2026:88211
- externalhttps://access.redhat.com/security/updates/classification/#moderate
- externalhttps://bugzilla.redhat.com/show_bug.cgi?id=2497929
- externalhttps://bugzilla.redhat.com/show_bug.cgi?id=2497935
- externalhttps://bugzilla.redhat.com/show_bug.cgi?id=2497938
- externalhttps://bugzilla.redhat.com/show_bug.cgi?id=2497946
- externalhttps://bugzilla.redhat.com/show_bug.cgi?id=2514321
- selfhttps://security.access.redhat.com/data/csaf/v2/advisories/2026/rhsa-2026_88211.json