Critical · 9.8 CVE-2026-43379 EUVD-2026-28685GHSA-wvq8-6v44-2qvw

ksmbd: fix use-after-free in smb_lazy_parent_lease_break_close()

Published May 8, 2026 · Updated Aug 5, 2026 · Assigned by Linux

Vendor: Linux Product: Linux Package: linux Package: linux Package: linux-allwinner-5.19 Package: linux-aws Package: linux-aws-5.0 Package: linux-aws-5.11 Package: linux-aws-5.13 Package: linux-aws-5.15 Package: linux-aws-5.19 Package: linux-aws-5.3 Package: linux-aws-5.8 Package: linux-aws-6.14 Package: linux-aws-6.17 Package: linux-aws-6.2 Package: linux-aws-6.5 Package: linux-aws-6.8 Package: linux-aws-fips Package: linux-azure Package: linux-azure-5.11 Package: linux-azure-5.13 Package: linux-azure-5.15 Package: linux-azure-5.19 Package: linux-azure-5.3 Package: linux-azure-5.8 Package: linux-azure-6.11 Package: linux-azure-6.14 Package: linux-azure-6.17 Package: linux-azure-6.2 Package: linux-azure-6.5 Package: linux-azure-6.8 Package: linux-azure-edge Package: linux-azure-fde Package: linux-azure-fde-5.15 Package: linux-azure-fde-5.19 Package: linux-azure-fde-6.14 Package: linux-azure-fde-6.17 Package: linux-azure-fde-6.2 Package: linux-azure-fde-6.8 Package: linux-azure-fips Package: linux-azure-nvidia Package: linux-azure-nvidia-6.14 Package: linux-bluefield Package: linux-fips Package: linux-gcp Package: linux-gcp-5.11 Package: linux-gcp-5.13 Package: linux-gcp-5.15 Package: linux-gcp-5.19 Package: linux-gcp-5.3 Package: linux-gcp-5.8 Package: linux-gcp-6.11 Package: linux-gcp-6.14 Package: linux-gcp-6.17 Package: linux-gcp-6.2 Package: linux-gcp-6.5 Package: linux-gcp-6.8 Package: linux-gcp-fips Package: linux-gke Package: linux-gke-4.15 Package: linux-gke-5.15 Package: linux-gke-5.4 Package: linux-gkeop Package: linux-gkeop-5.15 Package: linux-gkeop-5.4 Package: linux-hwe Package: linux-hwe-5.11 Package: linux-hwe-5.13 Package: linux-hwe-5.15 Package: linux-hwe-5.19 Package: linux-hwe-5.8 Package: linux-hwe-6.11 Package: linux-hwe-6.14 Package: linux-hwe-6.17 Package: linux-hwe-6.2 Package: linux-hwe-6.5 Package: linux-hwe-6.8 Package: linux-hwe-edge Package: linux-ibm Package: linux-ibm-5.15 Package: linux-ibm-6.8 Package: linux-intel-5.13 Package: linux-intel-iot-realtime Package: linux-intel-iotg Package: linux-intel-iotg-5.15 Package: linux-kvm Package: linux-lowlatency Package: linux-lowlatency-hwe-5.15 Package: linux-lowlatency-hwe-5.19 Package: linux-lowlatency-hwe-6.11 Package: linux-lowlatency-hwe-6.2 Package: linux-lowlatency-hwe-6.5 Package: linux-lowlatency-hwe-6.8 Package: linux-nvidia Package: linux-nvidia-6.11 Package: linux-nvidia-6.17 Package: linux-nvidia-6.2 Package: linux-nvidia-6.5 Package: linux-nvidia-6.8 Package: linux-nvidia-lowlatency Package: linux-nvidia-tegra Package: linux-nvidia-tegra-5.15 Package: linux-nvidia-tegra-igx Package: linux-oem Package: linux-oem-5.10 Package: linux-oem-5.13 Package: linux-oem-5.14 Package: linux-oem-5.17 Package: linux-oem-5.6 Package: linux-oem-6.0 Package: linux-oem-6.1 Package: linux-oem-6.11 Package: linux-oem-6.14 Package: linux-oem-6.17 Package: linux-oem-6.5 Package: linux-oem-6.8 Package: linux-oracle Package: linux-oracle-5.0 Package: linux-oracle-5.11 Package: linux-oracle-5.13 Package: linux-oracle-5.15 Package: linux-oracle-5.3 Package: linux-oracle-5.8 Package: linux-oracle-6.14 Package: linux-oracle-6.17 Package: linux-oracle-6.5 Package: linux-oracle-6.8 Package: linux-raspi Package: linux-raspi-realtime Package: linux-raspi2 Package: linux-realtime Package: linux-realtime-6.14 Package: linux-realtime-6.17 Package: linux-realtime-6.8 Package: linux-riscv Package: linux-riscv-5.11 Package: linux-riscv-5.15 Package: linux-riscv-5.19 Package: linux-riscv-5.8 Package: linux-riscv-6.14 Package: linux-riscv-6.17 Package: linux-riscv-6.5 Package: linux-riscv-6.8 Package: linux-starfive-5.19 Package: linux-starfive-6.2 Package: linux-starfive-6.5 Package: linux-vmware Package: linux-xilinx Package: linux-xilinx-zynqmp Platform: Linux Ecosystem: Debian Ecosystem: Ubuntu

Description

In the Linux kernel, the following vulnerability has been resolved:

ksmbd: fix use-after-free in smb_lazy_parent_lease_break_close()

opinfo pointer obtained via rcu_dereference(fp->f_opinfo) is being
accessed after rcu_read_unlock() has been called. This creates a
race condition where the memory could be freed by a concurrent
writer between the unlock and the subsequent pointer dereferences
(opinfo->is_lease, etc.), leading to a use-after-free.

Affected products

Vendor	Product	Affected	Fixed
Linux	Linux	6.6.32 – < 6.6.130, 6.9	6.6.130

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

Debian

Security tracker ↗

Release	Package	Fixed in	Advisory
Debian 14	linux	6.19.10-1	—
Debian 13	linux	6.12.85-1	—

Ubuntu

Security tracker ↗

Release	Package	Fixed in	Advisory
Ubuntu Nvidia-BlueField 24.04 LTS	linux-bluefield	No fix yet	—
Ubuntu Nvidia-BlueField 22.04 LTS	linux-bluefield	No fix yet	—
Ubuntu 25.10	linux +8	No fix yet	—
Ubuntu 24.04 LTS	linux +38	No fix yet	—
Ubuntu 24.04 LTS	linux-azure-6.17	6.17.0-1022.22	USN-8636-1
Ubuntu 24.04 LTS	linux-gcp-6.17	6.17.0-1022.25	USN-8636-1
Ubuntu 24.04 LTS	linux-hwe-6.17	6.17.0-42.42	USN-8636-1
Ubuntu 24.04 LTS	linux-nvidia-6.17	6.17.0-1031.31	USN-8669-1
Ubuntu 24.04 LTS	linux-oem-6.17	6.17.0-1032.32	USN-8636-1
Ubuntu 24.04 LTS	linux-oracle-6.17	6.17.0-1020.20	USN-8636-2
Ubuntu 22.04 LTS	linux +59	No fix yet	—

Show 8 more (older releases, extended support, other products)

Release	Package	Fixed in	Advisory
Ubuntu 20.04 LTS	linux-gke +28	No fix yet	—
Ubuntu 18.04 LTS	linux-gcp +14	No fix yet	—
Ubuntu 16.04 LTS	linux-hwe-edge	No fix yet	—
Ubuntu Pro Realtime 24.04 LTS	linux-realtime +2	No fix yet	—
Ubuntu Pro Realtime 24.04 LTS	linux-realtime-6.17	6.17.0-1019.22	USN-8636-1
Ubuntu Pro Realtime 22.04 LTS	linux-realtime +2	No fix yet	—
Ubuntu Pro FIPS-updates 24.04 LTS	linux-fips +3	No fix yet	—
Ubuntu Pro FIPS-updates 22.04 LTS	linux-fips +3	No fix yet	—
Ubuntu Pro 20.04 LTS	linux-aws-5.15 +10	No fix yet	—

Advisories 4

WID-SEC-2026-1454 Linux Kernel: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 11, 2026
USN-8669-1 linux-nvidia-6.17 vulnerabilities Ubuntu Security Notices (USN) · Nov 6, 2026
USN-8636-2 linux-oracle-6.17 vulnerabilities Ubuntu Security Notices (USN) · Nov 6, 2026
USN-8636-1 linux-azure-6.17, linux-gcp-6.17, linux-hwe-6.17, linux-oem-6.17, linux-realtime-6.17 vulnerabilities Ubuntu Security Notices (USN) · Nov 6, 2026

References