In the Linux kernel, the following vulnerability has been resolved:
ksmbd: validate owner of durable handle on reconnect
Currently, ksmbd does not verify if the user attempting to reconnect to a durable handle is the same user who originally opened the file. This allows any authenticated user to hijack an orphaned durable handle by predicting or brute-forcing the persistent ID.
According to MS-SMB2, the server MUST verify that the SecurityContext of the reconnect request matches the SecurityContext associated with the existing open. Add a durableowner structure to ksmbdfile to store the original opener's UID, GID, and account name. and catpure the owner information when a file handle becomes orphaned. and implementing ksmbdvfscomparedurableowner() to validate the identity of the requester during SMB2_CREATE (DHnC).
{
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31717.json",
"cna_assigner": "Linux"
}