CVE-2026-99278
Received
Received - Intake
ksmbd Session Limit Bypass Vulnerability
Vulnerability report for CVE-2026-99278, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-11-07
Last updated on: 2026-11-07
Assigner: kernel.org
Description
Description
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: limit sessions on each connection
The pending setup limit only counts InProgress sessions. A client can
complete authentication repeatedly and retain an unbounded number of Valid
sessions on one connection.
Reserve a connection slot before allocating a session and retain a
connection reference while authentication is in progress. The first SMB3
channel takes over that reservation; binding to another connection reserves
one slot there. Reauthentication and authentication continuation reuse the
existing reservation. Return slots on allocation or insertion failure,
channel removal, and final session destruction.
Accept max_sessions_per_connection in reserved startup-request space and
default to 64 when older tools leave it zero. Keep the request size and
existing field offsets unchanged. Expose the configured limit in procfs.
The existing connection limits bound the aggregate number of sessions
without a separate global session allocation limit.
CVSS Scores
EPSS Scores
| Probability: | |
| Percentile: |
Meta Information
Affected Vendors & Products
Currently, no data is known.
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-UNKNOWN |
