CVE-2026-52911

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.

Gravité et risque d'exploitation

CVE-2026-52911 obtient un score CVSS de 8.8/10, soit une gravité élevée. Selon le modèle EPSS, la probabilité qu'elle soit exploitée dans les 30 prochains jours est de 0.66 %, ce qui la place devant 50.8 % des CVE référencées.

Que faire ?

• Vérifiez si Linux (versions <=6.1.*, <=7.0.*, <=6.12.*, <e3a93ce6e25757b8f375e38b8f91e1d9da4edc1a, 0, <2cc8a4db633b10715450b291c1343859a4b2c509, 6.18.33, <974c1c224e85549dc3459f3bb2255bbbdd2b9372, 5.15.209, 6.12.91, <=6.6.*, 6.1.175, <b0da97c034b6107d14e537e212d4ce8b22109a58, <5.15, 6.6.141, 7.1, 5.15, <=6.18.*, 7.0.10, <1e2bec062c5c9ec282636715166056d0998d746d, <=*, f5a544e3bab78142207e0242d22442db85ba1eff, <=5.15.*, <1ff46c9915c1cbf454db58a8cb87f7cac818e6a6, <e74c00c6af428a39e564cdc5bd3a3648c6d8de87) est présent sur votre parc.
• Appliquez le correctif ou la version corrigée indiqués dans les références de l'éditeur.
• À défaut de correctif, limitez l'exposition (filtrage réseau, désactivation du composant).
• Automatisez la détection : les agents CVE Heimdall (gratuits, open source) corrèlent l'inventaire de vos serveurs avec la base CVE.

Références

• https://git.kernel.org/stable/c/e74c00c6af428a39e564cdc5bd3a3648c6d8de87
• https://git.kernel.org/stable/c/e3a93ce6e25757b8f375e38b8f91e1d9da4edc1a
• https://git.kernel.org/stable/c/1ff46c9915c1cbf454db58a8cb87f7cac818e6a6
• https://git.kernel.org/stable/c/974c1c224e85549dc3459f3bb2255bbbdd2b9372
• https://git.kernel.org/stable/c/2cc8a4db633b10715450b291c1343859a4b2c509
• https://git.kernel.org/stable/c/1e2bec062c5c9ec282636715166056d0998d746d
• https://git.kernel.org/stable/c/b0da97c034b6107d14e537e212d4ce8b22109a58