USN-8937-1: OpenSSH vulnerabilities
Publication date
19 October 2026
Overview
Several security issues were fixed in OpenSSH.
Releases
Packages
- openssh - secure shell (SSH) for secure access to remote machines
- openssh-gssapi - secure shell (SSH) for secure access to remote machines
Details
It was discovered that OpenSSH's sftp client incorrectly handled paths
returned by the server during a recursive copy operation. A remote attacker
controlling the server could possibly use this issue to write files to
unintended locations. (CVE-2026-106552)
It was discovered that OpenSSH's sshd server incorrectly handled
GSSAPIAuthentication state across authentication attempts. An attacker
could possibly use this issue to obtain credentials from a previous failed
authentication attempt. (CVE-2026-106553, CVE-2026-106555)
It was discovered that OpenSSH incorrectly used an LZ77 dictionary coder
during compression. An attacker could possibly use this issue to obtain
sensitive information. (CVE-2026-106582)
It was discovered that OpenSSH's ssh client incorrectly allowed...
It was discovered that OpenSSH's sftp client incorrectly handled paths
returned by the server during a recursive copy operation. A remote attacker
controlling the server could possibly use this issue to write files to
unintended locations. (CVE-2026-106552)
It was discovered that OpenSSH's sshd server incorrectly handled
GSSAPIAuthentication state across authentication attempts. An attacker
could possibly use this issue to obtain credentials from a previous failed
authentication attempt. (CVE-2026-106553, CVE-2026-106555)
It was discovered that OpenSSH incorrectly used an LZ77 dictionary coder
during compression. An attacker could possibly use this issue to obtain
sensitive information. (CVE-2026-106582)
It was discovered that OpenSSH's ssh client incorrectly allowed special
characters in command-line usernames. An attacker could possibly use this
issue to inject arbitrary commands via specially crafted usernames.
(CVE-2026-106583)
It was discovered that OpenSSH's ssh-keygen incorrectly handled Daylight
Saving Time when converting dates. An attacker could possibly use this
issue to cause certificates to have incorrect expiration times.
(CVE-2026-106584)
It was discovered that OpenSSH did not check whether the maximum packet
length was exceeded during decompression. A remote attacker could possibly
use this issue to cause a denial of service. (CVE-2026-106585)
It was discovered that OpenSSH's sshd server incorrectly applied the
restrict keyword from authorized_keys to tunnel forwarding requests. A
local attacker with an authorized key could possibly use this issue to
bypass intended tunnel forwarding restrictions. (CVE-2026-106586)
It was discovered that OpenSSH's sshd server incorrectly handled certain
configuration options that accept a "none" value. An attacker could
possibly use this issue to cause OpenSSH to behave unexpectedly.
(CVE-2026-106587)
Update instructions
In general, a standard system update will make all the necessary changes.
Learn more about how to get the fixes.The problem can be corrected by updating your system to the following package versions:
| Ubuntu Release | Package Version | ||
|---|---|---|---|
| 26.10 stonking | openssh-client – 1:10.5p1-1ubuntu3.1 | ||
| openssh-client-gssapi – 1:10.5p1-1ubuntu3.1 | |||
| openssh-server – 1:10.5p1-1ubuntu3.1 | |||
| openssh-server-gssapi – 1:10.5p1-1ubuntu3.1 | |||
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