GHSA-hxmm-jmj9-253j · Severity: unknown — In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix NULL-deref of...
In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix NULL-deref of opinfo->conn in oplock/lease break notifiers smb2_oplock_break_noti() and smb2_lease_break_noti() read opinfo->conn into a local with neither READ_ONCE() nor a NULL check. Both run from oplock_break() after opinfo_get_list() has dropped ci->m_lock, so a concurrent SMB2 LOGOFF (session_fd_check()) can set op->conn = NULL under ci->m_lock within that window. ksmbd_conn_r_count_inc(conn) then writes through NULL at offset 0xc4 -- a remotely triggerable oops. Guard both reads the way compare_guid_key() already does: read opinfo->conn with READ_ONCE() and return early if it is NULL, before allocating the work struct so nothing leaks. A NULL conn means the client is gone and the break is moot, so return 0; oplock_break() treats that as success and runs the normal teardown.
Conclusion & alert: CVE-2026-53271 is rated Low Risk (5.9/100): low exploitation likelihood (EPSS 0.16%). Mandatory action: Low composite risk—no urgent action required; patch on your normal maintenance cycle and revisit priority if CVSS or EPSS increases.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-06-25 | — | 0.16% | — |
Full EPSS history (1 record total)
CVSS metrics for this CVE.
No CVSS data in dataset for this CVE.
GHSA-hxmm-jmj9-253j · Severity: unknown — In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix NULL-deref of...
| vendor | priority | summary | link |
|---|---|---|---|
debian
|
unimportant | CVE-2026-53271 unimportant priority: Debian including 1 source packages (linux), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. | https://security-tracker.debian.org/tracker/CVE-2026-53271 |
redhat
|
— | — | https://access.redhat.com/security/cve/CVE-2026-53271 |
suse
|
medium | CVE-2026-53271 severity moderate: SUSE including 20 source package names (cluster-md-kmp-default, dlm-kmp-default, …), 184 product×package rows across 36 product lines (SUSE Linux Enterprise High Availability Extension 15 SP7, SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS, … (36 product lines)): Known Not Affected 184. | https://www.suse.com/security/cve/CVE-2026-53271/ |
ubuntu
|
medium | CVE-2026-53271 medium priority: Ubuntu including 161 source packages (linux, linux-allwinner-5.19, …), 1449 status rows across 9 suites (bionic, focal, jammy, noble, questing, resolute, trusty, upstream, xenial): DNE 1044, ignored 172, not-affected 112, released 87, needed 33, needs-triage 1. | https://ubuntu.com/security/CVE-2026-53271 |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| linux | linux_kernel | >= 6.6.32, < 6.6.143 | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| linux | linux_kernel | >= 6.9, < 6.12.94 | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| linux | linux_kernel | >= 6.9, < 6.18.36 | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| linux | linux_kernel | >= 6.9, < 7.0.13 | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| linux | linux_kernel | >= 6.9, < 7.1 | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |