RHSA-2026:21398 - Security Advisory

Topic

An update for openssh is now available for Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support, Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions, and Red Hat Enterprise Linux 8.6 Telecommunications Update Service.

Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

Description

OpenSSH is an SSH protocol implementation supported by a number of Linux, UNIX, and similar operating systems. It includes the core files necessary for both the OpenSSH client and server.

Security Fix(es):

• OpenSSH: OpenSSH: Privilege escalation via scp legacy protocol when not preserving file mode (CVE-2026-35385)
• OpenSSH: OpenSSH: Security bypass via mishandling of authorized_keys principals option (CVE-2026-35414)
• OpenSSH: OpenSSH: Information disclosure due to unintended cryptographic algorithm usage (CVE-2026-35387)
• OpenSSH: OpenSSH: Low integrity impact from unconfirmed proxy-mode multiplexing sessions (CVE-2026-35388)
• OpenSSH: OpenSSH: Arbitrary command execution via shell metacharacters in username (CVE-2026-35386)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Solution

For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

Affected Products

• Red Hat Enterprise Linux for x86_64 - Extended Life Cycle Long Life 8.6 x86_64
• Red Hat Enterprise Linux Server - AUS 8.6 x86_64
• Red Hat Enterprise Linux Server - TUS 8.6 x86_64
• Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions 8.6 ppc64le
• Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 8.6 x86_64
• Red Hat Enterprise Linux for ARM 64 - Extended Life Cycle Long Life 8.6 aarch64
• Red Hat Enterprise Linux for Power, little endian - Extended Life Cycle Long Life 8.6 ppc64le
• Red Hat Enterprise Linux for IBM z Systems - Extended Life Cycle Long Life 8.6 s390x

Fixes

• BZ - 2454469 - CVE-2026-35385 OpenSSH: OpenSSH: Privilege escalation via scp legacy protocol when not preserving file mode
• BZ - 2454490 - CVE-2026-35414 OpenSSH: OpenSSH: Security bypass via mishandling of authorized_keys principals option
• BZ - 2454494 - CVE-2026-35387 OpenSSH: OpenSSH: Information disclosure due to unintended cryptographic algorithm usage
• BZ - 2454500 - CVE-2026-35388 OpenSSH: OpenSSH: Low integrity impact from unconfirmed proxy-mode multiplexing sessions
• BZ - 2454506 - CVE-2026-35386 OpenSSH: OpenSSH: Arbitrary command execution via shell metacharacters in username

CVEs

• CVE-2026-35385
• CVE-2026-35386
• CVE-2026-35387
• CVE-2026-35388
• CVE-2026-35414

References

• https://access.redhat.com/security/updates/classification/#important