{"cve":"CVE-2026-53271","nvd":{"published":"2026-06-25T09:16:45.247","modified":"2026-07-08T04:01:39.257","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fix NULL-deref of opinfo->conn in oplock/lease break notifiers\n\nsmb2_oplock_break_noti() and smb2_lease_break_noti() read opinfo->conn\ninto a local with neither READ_ONCE() nor a NULL check.  Both run from\noplock_break() after opinfo_get_list() has dropped ci->m_lock, so a\nconcurrent SMB2 LOGOFF (session_fd_check()) can set op->conn = NULL\nunder ci->m_lock within that window.  ksmbd_conn_r_count_inc(conn) then\nwrites through NULL at offset 0xc4 -- a remotely triggerable oops.\n\nGuard both reads the way compare_guid_key() already does: read\nopinfo->conn with READ_ONCE() and return early if it is NULL, before\nallocating the work struct so nothing leaks.  A NULL conn means the\nclient is gone and the break is moot, so return 0; oplock_break() treats\nthat as success and runs the normal teardown.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-476"],"references":["https://git.kernel.org/stable/c/1ff58dcfcab434ebb51649da33774fbb8e1f7b67","https://git.kernel.org/stable/c/75e33deda658c1ab3a9336cbdb1436536f9b3660","https://git.kernel.org/stable/c/945a86b21b40fb17183f5b27461baa6f03e2467f","https://git.kernel.org/stable/c/b003086d76968298f22e7cf62239833b5a3a06b1","https://git.kernel.org/stable/c/e735dbd489e3ea02be78dba991056fe1138be51e"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:41:17.107060303+00:00"},"epss":{"cve":"CVE-2026-53271","score":0.00162,"percentile":0.05347,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}