Unscored CVE-2026-68130 EUVD-2026-55511GHSA-cjmw-xwhw-8r5x

ksmbd: defer destroy_previous_session() until after NTLM authentication

Published Aug 10, 2026 · Updated Aug 23, 2026 · Assigned by Linux

Vendor: Linux Product: Linux Package: linux Package: linux Package: linux-6.12 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-7.0 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-7.0 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-fde-7.0 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-7.0 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-7.0 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-7.0 Package: linux-nvidia-bos 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-oem-7.0 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-oracle-7.0 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-riscv-7.0 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: defer destroy_previous_session() until after NTLM authentication

In ntlm_authenticate(), destroy_previous_session() is called using a
user pointer resolved from the client-supplied NTLM blob username field
before the NTLMv2 response is validated. An authenticated attacker can
set the NTLM blob username to match a victim account and set
PreviousSessionId to the victim's session ID; destroy_previous_session()
destroys the victim's session while ksmbd_decode_ntlmssp_auth_blob()
subsequently rejects the request with -EPERM.

Move destroy_previous_session() and the prev_id assignment to after
ksmbd_decode_ntlmssp_auth_blob() returns success and use sess->user
rather than the pre-authentication lookup result. This matches the
ordering already used by krb5_authenticate(), where
destroy_previous_session() is called only after
ksmbd_krb5_authenticate() returns success.

Affected products

Vendor	Product	Affected	Fixed
Linux	Linux	5.15	5.15.217

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	7.1.6-1	—
Debian 13	linux	6.12.101-1	—
Debian 12	linux	6.1.187-1	—
Debian 12	linux-6.12	6.12.101-1~deb12u1	—

Ubuntu

Security tracker ↗

Release	Package	Fixed in	Advisory
Ubuntu Nvidia-BlueField 24.04 LTS	linux-bluefield	6.8.0-1033.38	—
Ubuntu Nvidia-BlueField 22.04 LTS	linux-bluefield	5.15.0-1103.105	—
Ubuntu 26.04 LTS	linux	7.0.0-38.38	USN-8887-1
Ubuntu 26.04 LTS	linux-aws +1	7.0.0-1014.14	USN-8887-1
Ubuntu 26.04 LTS	linux-azure	7.0.0-1017.17	USN-8888-1
Ubuntu 26.04 LTS	linux-azure-fde	7.0.0-1016.16	USN-8888-1
Ubuntu 26.04 LTS	linux-gke	7.0.0-1008.9	USN-8887-1
Ubuntu 26.04 LTS	linux-ibm +1	7.0.0-1015.15	USN-8889-1, USN-8887-1
Ubuntu 26.04 LTS	linux-nvidia	7.0.0-1025.26	USN-9043-1
Ubuntu 26.04 LTS	linux-nvidia-bos	7.0.0-2022.23	USN-9003-1
Ubuntu 26.04 LTS	linux-oracle	7.0.0-1013.13	USN-8887-1
Ubuntu 26.04 LTS	linux-raspi	7.0.0-1023.23	USN-9021-1
Ubuntu 26.04 LTS	linux-riscv +1	7.0.0-38.38.1	USN-8887-1
Ubuntu 24.04 LTS	linux	6.8.0-147.147	USN-8917-1
Ubuntu 24.04 LTS	linux-aws +1	6.8.0-1067.70	USN-9024-1, USN-8917-1
Ubuntu 24.04 LTS	linux-aws-7.0 +1	7.0.0-1014.14~24.04.1	USN-8887-3, USN-8887-2
Ubuntu 24.04 LTS	linux-azure-7.0	7.0.0-1017.17~24.04.1	USN-8888-2
Ubuntu 24.04 LTS	linux-azure-fde	6.8.0-1069.76	USN-8918-1
Ubuntu 24.04 LTS	linux-azure-fde-7.0	7.0.0-1016.16~24.04.1	USN-8888-2
Ubuntu 24.04 LTS	linux-gcp +1	6.8.0-1071.79	USN-8918-1, USN-8917-1
Ubuntu 24.04 LTS	linux-gke	6.8.0-1066.74	USN-8917-1
Ubuntu 24.04 LTS	linux-gkeop	6.8.0-1052.56	USN-8917-1
Ubuntu 24.04 LTS	linux-hwe-7.0	7.0.0-38.38~24.04.4	USN-8887-3
Ubuntu 24.04 LTS	linux-ibm	6.8.0-1067.68	USN-8917-1
Ubuntu 24.04 LTS	linux-lowlatency	6.8.0-147.147.1	USN-8917-1
Ubuntu 24.04 LTS	linux-nvidia-7.0	7.0.0-1024.25~24.04.1	USN-9003-1
Ubuntu 24.04 LTS	linux-nvidia-lowlatency	6.8.0-1067.70.1	USN-9040-1
Ubuntu 24.04 LTS	linux-oracle	6.8.0-1064.67	USN-8917-1
Ubuntu 24.04 LTS	linux-oracle-7.0	7.0.0-1013.13~24.04.1	USN-8887-3
Ubuntu 24.04 LTS	linux-raspi	6.8.0-1068.72	USN-9025-1
Ubuntu 24.04 LTS	linux-riscv +30	No fix yet	—
Ubuntu 24.04 LTS	linux-riscv-7.0	7.0.0-38.38.1~24.04.1	—
Ubuntu 24.04 LTS	linux-vmware	6.8.0-1008.8	—
Ubuntu 22.04 LTS	linux	5.15.0-202.212	USN-8961-1
Ubuntu 22.04 LTS	linux-aws	5.15.0-1119.126	USN-8961-1
Ubuntu 22.04 LTS	linux-aws-6.8	6.8.0-1069.74~22.04.1	USN-9024-1
Ubuntu 22.04 LTS	linux-azure	5.15.0-1125.134	USN-8961-1
Ubuntu 22.04 LTS	linux-azure-6.8	6.8.0-1073.82~22.04.1	USN-9026-1
Ubuntu 22.04 LTS	linux-azure-fde	5.15.0-1124.133	—
Ubuntu 22.04 LTS	linux-azure-fde-6.8	6.8.0-1071.78~22.04.1	USN-9026-1
Ubuntu 22.04 LTS	linux-gcp	5.15.0-1120.130	USN-8961-1
Ubuntu 22.04 LTS	linux-gcp-6.8	6.8.0-1073.81~22.04.1	USN-9024-1
Ubuntu 22.04 LTS	linux-gke	5.15.0-1115.121	USN-8961-1
Ubuntu 22.04 LTS	linux-gkeop	5.15.0-1102.110	USN-8961-1
Ubuntu 22.04 LTS	linux-hwe-6.8	6.8.0-149.149~22.04.1	USN-9066-1
Ubuntu 22.04 LTS	linux-ibm	5.15.0-1113.117	USN-8961-1
Ubuntu 22.04 LTS	linux-ibm-6.8	6.8.0-1069.70~22.04.1	USN-9024-1
Ubuntu 22.04 LTS	linux-intel-iotg	5.15.0-1114.120	USN-8961-1
Ubuntu 22.04 LTS	linux-kvm	5.15.0-1111.116	USN-8961-1
Ubuntu 22.04 LTS	linux-lowlatency	5.15.0-197.207	USN-8961-1
Ubuntu 22.04 LTS	linux-lowlatency-hwe-6.8	6.8.0-149.149.1~22.04.1	USN-9024-1
Ubuntu 22.04 LTS	linux-nvidia	5.15.0-1114.115	USN-8961-1
Ubuntu 22.04 LTS	linux-nvidia-tegra	5.15.0-1070.72	USN-8963-1
Ubuntu 22.04 LTS	linux-nvidia-tegra-igx	5.15.0-1059.59	USN-8963-1
Ubuntu 22.04 LTS	linux-oracle	5.15.0-1116.122	USN-8961-1
Ubuntu 22.04 LTS	linux-oracle-6.8	6.8.0-1067.71~22.04.1	USN-9025-1
Ubuntu 22.04 LTS	linux-raspi	5.15.0-1113.116	USN-9029-1
Ubuntu 22.04 LTS	linux-riscv +34	No fix yet	—

Show 9 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-raspi-realtime	6.8.0-2056.58	USN-9025-1
Ubuntu Pro Realtime 24.04 LTS	linux-realtime	6.8.1-1062.63	USN-8917-1
Ubuntu Pro Realtime 24.04 LTS	linux-realtime-6.14 +1	No fix yet	—
Ubuntu Pro Realtime 22.04 LTS	linux-intel-iot-realtime	5.15.0-1111.115	USN-8961-1
Ubuntu Pro Realtime 22.04 LTS	linux-realtime	5.15.0-1118.127	USN-8961-1
Ubuntu Pro Realtime 22.04 LTS	linux-realtime-6.8	6.8.1-1064.65~22.04.1	USN-9024-1
Ubuntu Pro FIPS-updates 24.04 LTS	linux-aws-fips	6.8.0-1067.70+fips1	USN-8917-1
Ubuntu Pro FIPS-updates 24.04 LTS	linux-fips	6.8.0-147.147+fips1	USN-8917-1
Ubuntu Pro FIPS-updates 24.04 LTS	linux-gcp-fips +1	6.8.0-1071.79+fips1	USN-8918-1, USN-8917-1
Ubuntu Pro FIPS-updates 22.04 LTS	linux-aws-fips	5.15.0-1119.126+fips1	USN-8961-1
Ubuntu Pro FIPS-updates 22.04 LTS	linux-azure-fips	5.15.0-1125.134+fips1	USN-8961-1
Ubuntu Pro FIPS-updates 22.04 LTS	linux-fips	5.15.0-202.212+fips1	USN-8961-1
Ubuntu Pro FIPS-updates 22.04 LTS	linux-gcp-fips	5.15.0-1120.130+fips1	USN-8961-1
Ubuntu Pro FIPS-preview 22.04 LTS	linux-fips +3	No fix yet	—
Ubuntu Pro 20.04 LTS	linux-aws-5.15	5.15.0-1119.126~20.04.1	USN-8961-1
Ubuntu Pro 20.04 LTS	linux-azure-5.15	5.15.0-1125.134~20.04.1	USN-8961-1
Ubuntu Pro 20.04 LTS	linux-azure-fde-5.15	5.15.0-1124.133~20.04.1	USN-8961-1
Ubuntu Pro 20.04 LTS	linux-gcp-5.15	5.15.0-1120.130~20.04.1	USN-8961-1
Ubuntu Pro 20.04 LTS	linux-hwe-5.15	5.15.0-202.212~20.04.1	USN-8961-1
Ubuntu Pro 20.04 LTS	linux-ibm-5.15	5.15.0-1113.117~20.04.1	USN-8961-1
Ubuntu Pro 20.04 LTS	linux-intel-iotg-5.15	5.15.0-1114.120~20.04.1	USN-8961-1
Ubuntu Pro 20.04 LTS	linux-lowlatency-hwe-5.15	5.15.0-197.207~20.04.1	USN-8961-1
Ubuntu Pro 20.04 LTS	linux-nvidia-tegra-5.15	5.15.0-1070.72~20.04.1	USN-8963-1
Ubuntu Pro 20.04 LTS	linux-oracle-5.15	5.15.0-1116.122~20.04.1	USN-8961-1
Ubuntu Pro 20.04 LTS	linux-riscv-5.15	5.15.0-1113.117~20.04.2	—

Advisories 20

USN-9066-1 linux-hwe-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
USN-9021-1 linux-raspi vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
USN-9024-1 linux-aws-6.8, linux-gcp-6.8, linux-ibm-6.8, linux-lowlatency-hwe-6.8, linux-nvidia, linux-realtime-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
USN-9026-1 linux-azure-6.8, linux-azure-fde-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
WID-SEC-2026-2730 Linux Kernel: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 12, 2026
USN-9040-1 linux-nvidia-lowlatency vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
USN-9043-1 linux-nvidia vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
USN-8961-1 linux, linux-aws, linux-aws-5.15, linux-aws-fips, linux-azure, linux-azure-5.15, linux-azure-fde-5.15, linux-azure-fips, linux-fips, linux-gcp, linux-gcp-5.15, linux-gcp-fips, linux-gke, linux-gkeop, linux-hwe-5.15, linux-ibm, linux-ibm-5.15, linux-intel-iot-realtime, linux-intel-iotg, linux-intel-iotg-5.15, linux-kvm, linux-lowlatency, linux-lowlatency-hwe-5.15, linux-nvidia, linux-oracle, linux-oracle-5.15, linux-realtime vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
USN-8963-1 linux-nvidia-tegra, linux-nvidia-tegra-5.15, linux-nvidia-tegra-igx vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
USN-8917-1 linux, linux-aws, linux-aws-fips, linux-fips, linux-gcp, linux-gcp-fips, linux-gke, linux-gkeop, linux-ibm, linux-lowlatency, linux-oracle, linux-realtime vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
USN-9025-1 linux-oracle-6.8, linux-raspi, linux-raspi-realtime vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
USN-8887-1 linux, linux-aws, linux-gcp, linux-gke, linux-ibm, linux-oracle, linux-realtime vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
USN-9029-1 linux-raspi vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
USN-8887-3 linux-gcp-7.0, linux-hwe-7.0, linux-oracle-7.0 vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
USN-9003-1 linux-nvidia-7.0, linux-nvidia-bos vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
USN-8888-2 linux-azure-7.0, linux-azure-fde-7.0 vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
USN-8918-1 linux-azure, linux-azure-fde, linux-azure-fips vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
USN-8888-1 linux-azure, linux-azure-fde vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
USN-8887-2 linux-aws-7.0 vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
USN-8889-1 linux-oem-7.0 vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026

References