Ended sessions not reclaimed in ksmbd in the Linux kernel
Key facts
- Attack vector
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- Privileges required
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- User interaction
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- Attack complexity
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- Impact type
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- Confidentiality · integrity · availability
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- Fix status
- Fixed
No CVSS vector from any source. Fix status from CNA.
Summary
The ksmbd SMB server in the Linux kernel has an affected range from 7.2.8 before 7.3 and another from 7.3, with fixes listed in 7.3, 7.3.2 and 7.4-rc1. Sessions that end through logoff or replacement stay in the Expired state and keep their memory and connection slots when no further setup arrives on the owning connection. The flaw is a failure to reclaim ended sessions from the global session table.
Written with Claude Haiku 5.5 from the sources below · 2026-11-08
Description from the CNA
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.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
Remediation
Update the Linux kernel to a fixed version: 7.3, 7.3.2 or 7.4-rc1, depending on the release line in use.
Written with Claude Haiku 5.5 from the sources below · 2026-11-08
- Fix · CNA Linux (Linux) Fixed in 7.3
- Fix · CNA Linux (Linux) Fixed in 7.3.2, 7.4-rc1
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
Not affected: 7 products
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
- Red Hat OpenShift Container Platform 4
- Red Hat OpenShift Container Platform 5
Timeline
- 2026-11-07 Threatist record created from CVE-2026-99279
- 2026-11-07 Alias added: GHSA-5c46-592c-382g
- 2026-11-08 Affected versions changed · Red Hat
- 2026-11-08 CVSS score added · Red Hat
References
More Linux vulnerabilities
- TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
- TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
- TI-2021-02452 Incorrect authorization in Ubuntu linux kernel KEVCVSS 3.1HIGH 8.8
- TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
- TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
Sources
- CVE-2026-99279 · CVE Program
- CVE-2026-99279 · NVD
- GHSA-5c46-592c-382g · GitHub Advisory Database · CC BY 4.0
- CVE-2026-99279 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences