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QSN-8721-1: OpenSSH vulnerabilities

September 3, 2026

Summary

Several security issues were fixed in OpenSSH.

Details

It was discovered that OpenSSH's ssh-agent incorrectly handled interactions between agent locking and the session-bind@openssh.com extension. A remote attacker with access to a forwarded agent connection could possibly use this issue to perform operations that should only be available locally, such as adding tokens or using keys. (CVE-2026-73281)

It was discovered that OpenSSH's ssh client incorrectly handled concurrent remote-forwarding operations. A remote attacker could possibly use this issue to cause a use-after-free condition, resulting in a denial of service or the execution of arbitrary code. (CVE-2026-73282)

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-2026-73283)

Affected QuantaStor releases

ReleasePlatformPackageExposureShipped versionFixed versionStatus
6.9.1.001Ubuntu 22.04 LTSopenssh-clientInternally-facing1:8.9p1-3ubuntu0.181:8.9p1-3ubuntu0.17Fixed in this release
6.9.1.001Ubuntu 22.04 LTSopenssh-serverExternally-facing1:8.9p1-3ubuntu0.181:8.9p1-3ubuntu0.17Fixed in this release
6.9.1.001Ubuntu 22.04 LTSopenssh-sftp-serverInternally-facing1:8.9p1-3ubuntu0.181:8.9p1-3ubuntu0.17Fixed in this release
6.9.0.464Ubuntu 22.04 LTSopenssh-clientInternally-facing1:8.9p1-3ubuntu0.181:8.9p1-3ubuntu0.17Fixed in this release
6.9.0.464Ubuntu 22.04 LTSopenssh-serverExternally-facing1:8.9p1-3ubuntu0.181:8.9p1-3ubuntu0.17Fixed in this release
6.9.0.464Ubuntu 22.04 LTSopenssh-sftp-serverInternally-facing1:8.9p1-3ubuntu0.181:8.9p1-3ubuntu0.17Fixed in this release
6.8.6.015Ubuntu 22.04 LTSopenssh-clientInternally-facing1:8.9p1-3ubuntu0.171:8.9p1-3ubuntu0.17Fixed in this release
6.8.6.015Ubuntu 22.04 LTSopenssh-serverExternally-facing1:8.9p1-3ubuntu0.171:8.9p1-3ubuntu0.17Fixed in this release
6.8.6.015Ubuntu 22.04 LTSopenssh-sftp-serverInternally-facing1:8.9p1-3ubuntu0.171:8.9p1-3ubuntu0.17Fixed in this release
6.8.5.018Ubuntu 22.04 LTSopenssh-clientInternally-facing1:8.9p1-3ubuntu0.161:8.9p1-3ubuntu0.17Fixed by QuantaStor security update
6.8.5.018Ubuntu 22.04 LTSopenssh-serverExternally-facing1:8.9p1-3ubuntu0.161:8.9p1-3ubuntu0.17Fixed by QuantaStor security update
6.8.5.018Ubuntu 22.04 LTSopenssh-sftp-serverInternally-facing1:8.9p1-3ubuntu0.161:8.9p1-3ubuntu0.17Fixed by QuantaStor security update
6.8.4.038Ubuntu 22.04 LTSopenssh-clientInternally-facing1:8.9p1-3ubuntu0.161:8.9p1-3ubuntu0.17Fixed by QuantaStor security update
6.8.4.038Ubuntu 22.04 LTSopenssh-serverExternally-facing1:8.9p1-3ubuntu0.161:8.9p1-3ubuntu0.17Fixed by QuantaStor security update
6.8.4.038Ubuntu 22.04 LTSopenssh-sftp-serverInternally-facing1:8.9p1-3ubuntu0.161:8.9p1-3ubuntu0.17Fixed by QuantaStor security update
6.8.3.018Ubuntu 22.04 LTSopenssh-clientInternally-facing1:8.9p1-3ubuntu0.161:8.9p1-3ubuntu0.17Fixed by QuantaStor security update
6.8.3.018Ubuntu 22.04 LTSopenssh-serverExternally-facing1:8.9p1-3ubuntu0.161:8.9p1-3ubuntu0.17Fixed by QuantaStor security update
6.8.3.018Ubuntu 22.04 LTSopenssh-sftp-serverInternally-facing1:8.9p1-3ubuntu0.161:8.9p1-3ubuntu0.17Fixed by QuantaStor security update
6.8.2.002Ubuntu 22.04 LTSopenssh-clientInternally-facing1:8.9p1-3ubuntu0.161:8.9p1-3ubuntu0.17Fixed by QuantaStor security update
6.8.2.002Ubuntu 22.04 LTSopenssh-serverExternally-facing1:8.9p1-3ubuntu0.161:8.9p1-3ubuntu0.17Fixed by QuantaStor security update
6.8.2.002Ubuntu 22.04 LTSopenssh-sftp-serverInternally-facing1:8.9p1-3ubuntu0.161:8.9p1-3ubuntu0.17Fixed by QuantaStor security update
6.8.1.007Ubuntu 22.04 LTSopenssh-clientInternally-facing1:8.9p1-3ubuntu0.161:8.9p1-3ubuntu0.17Fixed by QuantaStor security update
6.8.1.007Ubuntu 22.04 LTSopenssh-serverExternally-facing1:8.9p1-3ubuntu0.161:8.9p1-3ubuntu0.17Fixed by QuantaStor security update
6.8.1.007Ubuntu 22.04 LTSopenssh-sftp-serverInternally-facing1:8.9p1-3ubuntu0.161:8.9p1-3ubuntu0.17Fixed by QuantaStor security update
6.8.0.205Ubuntu 22.04 LTSopenssh-clientInternally-facing1:8.9p1-3ubuntu0.151:8.9p1-3ubuntu0.17Fixed by QuantaStor security update
6.8.0.205Ubuntu 22.04 LTSopenssh-serverExternally-facing1:8.9p1-3ubuntu0.151:8.9p1-3ubuntu0.17Fixed by QuantaStor security update
6.8.0.205Ubuntu 22.04 LTSopenssh-sftp-serverInternally-facing1:8.9p1-3ubuntu0.151:8.9p1-3ubuntu0.17Fixed by QuantaStor security update

Internally-facing: only accessible when logged into the QuantaStor console/ssh as the qadmin administrative sudo user; generally lower priority. Externally-facing: part of a service the storage platform presents on the network (or the kernel), so potentially reachable over the network.

CVEs

CVE-2026-73281, CVE-2026-73283, CVE-2026-73282

References

https://ubuntu.com/security/notices/USN-8721-1

https://nvd.nist.gov/vuln/detail/CVE-2026-73281

https://nvd.nist.gov/vuln/detail/CVE-2026-73283

https://nvd.nist.gov/vuln/detail/CVE-2026-73282

Update

Fixes marked Fixed by QuantaStor security update are applied by upgrading QuantaStor with security patches included (Upgrade Manager). Fixed package versions:

PlatformPackageVersion
Ubuntu 22.04 LTSopenssh1:8.9p1-3ubuntu0.17
Ubuntu 24.04 LTSopenssh1:9.6p1-3ubuntu13.19
resoluteopenssh1:10.2p1-2ubuntu3.6