CVE-2026-99279

Description

In the Linux kernel, the following vulnerability has been resolved: ksmbd: reclaim ended sessions on logoff and expiration LOGOFF and previous-session replacement leave sessions Expired with a zero credential expiry. Ended sessions can retain their memory and connection slots when no further setup arrives on the owning connection. Unpublish a logged-off session while the request reference keeps its response signing and encryption keys alive. Remove its procfs entry before dropping the table reference so a reader cannot remove its own entry on the last put. Clear proc_entry after removal to avoid removing it twice. Reclaim ended sessions from the global table in the existing expiration worker before it acquires conn_list_lock. Only select Expired sessions with zero credential expiry and no references beyond the table reference. Keep sessions whose Kerberos credentials expired available for reauthentication. Unlink the session from its setup connection and all channel connections, so SMB2 sessions and sessions with only secondary SMB3 channels are covered. The session already holds connection references, and sessions_table_lock prevents concurrent channel removal. Queue sessions on a separate disposal list, leaving their hash nodes unhashed, and remove procfs entries and drop table references outside the locks. Keep the pending setup check before allocating a new session so abandoned InProgress sessions can release their slots even at the connection limit. Retain the timeout and reference checks and dispose of those sessions outside the locks. Leave ended Expired sessions to the expiration worker.

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EPSS — Exploit Prediction

0.0012

Probability of exploitation

0.02%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

References

Other References

https://git.kernel.org/stable/c/1767a5e45dbf6a3b12105196dda4fb0ef80b9698 https://git.kernel.org/stable/c/26534ef335e92b028eb58e44d98d46a0e26af0ec

Frequently Asked Questions

What is CVE-2026-99279? +

In the Linux kernel, the following vulnerability has been resolved: ksmbd: reclaim ended sessions on logoff and expiration LOGOFF and previous-session replacement leave sessions Expired with a zero credential expiry. Ended sessions can retain their memory and connection slots when no further setup arrives on the owning connection. Unpublish a logged-off session while the request reference keeps its response signing and encryption keys alive. Remove its procfs entry before dropping the table reference so a reader cannot remove its own entry on the last put. Clear proc_entry after removal to avoid removing it twice. Reclaim ended sessions from the global table in the existing expiration worker before it acquires conn_list_lock. Only select Expired sessions with zero credential expiry and no references beyond the table reference. Keep sessions whose Kerberos credentials expired available for reauthentication. Unlink the session from its setup connection and all channel connections, so SMB2 sessions and sessions with only secondary SMB3 channels are covered. The session already holds connection references, and sessions_table_lock prevents concurrent channel removal. Queue sessions on a separate disposal list, leaving their hash nodes unhashed, and remove procfs entries and drop table references outside the locks. Keep the pending setup check before allocating a new session so abandoned InProgress sessions can release their slots even at the connection limit. Retain the timeout and reference checks and dispose of those sessions outside the locks. Leave ended Expired sessions to the expiration worker.

How do I check if I'm vulnerable to CVE-2026-99279? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.