CVE-2026-52911: In the Linux kernel, the following vulnerability has been resolved: ksmbd: scope conn->binding slowpath to bound sessions only When the binding SESS...

Description

In the Linux kernel, the following vulnerability has been resolved: ksmbd: scope conn->binding slowpath to bound sessions only When the binding SESSION_SETUP sets conn->binding = true, the flag stays set after the call so that the global session lookup in ksmbd_session_lookup_all() can find the session, which was not added to conn->sessions. Because the flag is connection-wide, the global lookup path will also resolve any other session by id if asked. Tighten the global lookup so that the returned session must have this connection registered in its channel xarray (sess->ksmbd_chann_list). The channel entry is installed by the existing binding_session path in ntlm_authenticate()/krb5_authenticate() when a SESSION_SETUP completes successfully, so this condition is a strict equivalent of "this connection has been accepted as a channel of this session". Connections that have not bound to a given session cannot reach it via the global table. The existing conn->binding gate for entering the slowpath is preserved so that non-binding connections keep the fast-path-only behavior, and the session->state check is unchanged.

Metrics

EPSS Probability

0.18%

7.4th percentile

Probability of exploitation in the next 30 days. Learn more

References

Timeline

Published: Jun 21, 2026
Last Modified: Jun 21, 2026
Status: Received

Frequently Asked Questions

What is CVE-2026-52911?

In the Linux kernel, the following vulnerability has been resolved: ksmbd: scope conn->binding slowpath to bound sessions only When the binding SESSION_SETUP sets conn->binding = true, the flag stays set after the call so that the global session lookup in ksmbd_session_lookup_all() can find the session, which was not added to conn->sessions. Because the flag is connection-wide, the global lookup path will also resolve any other session by id if asked. Tighten the global lookup so that the returned session must have this connection registered in its channel xarray (sess->ksmbd_chann_list). The channel entry is installed by the existing binding_session path in ntlm_authenticate()/krb5_authenticate() when a SESSION_SETUP completes successfully, so this condition is a strict equivalent of "this connection has been accepted as a channel of this session". Connections that have not bound to a given session cannot reach it via the global table. The existing conn->binding gate for entering the slowpath is preserved so that non-binding connections keep the fast-path-only behavior, and the session->state check is unchanged.

How severe is CVE-2026-52911?

Severity scoring for CVE-2026-52911 is pending analysis. The EPSS model estimates a 0.18% probability of exploitation in the next 30 days.

How do I fix CVE-2026-52911?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.