Log in Start free

Vulnerability · Published Jul 25, 2026 · Assigned by Linux

CVE-2026-64388smb/client: fix chown/chgrp with SMB3 POSIX Extensions

High 7.8

In plain English

A high-severity security flaw in Linux from Linux. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 3% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.8High
Exploit odds (30 days)0.1%top 97.1% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

In the Linux kernel, the following vulnerability has been resolved: smb/client: fix chown/chgrp with SMB3 POSIX Extensions Ownership (chown) and group (chgrp) modifications were being ignored when mounting with SMB3 POSIX Extensions unless CIFS_MOUNT_CIFS_ACL or CIFS_MOUNT_MODE_FROM_SID were also explicitly set. Fix this by checking for posix_extensions in cifs_setattr_nounix() when updating UID and GID, ensuring that id_mode_to_cifs_acl() is called to map and set the ownership/group information on the server.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12linuxno fix listedDEBIAN-CVE-2026-64388
Debian:13linux6.12.115-2DEBIAN-CVE-2026-64388
Debian:14linux7.1.4-1DEBIAN-CVE-2026-64388
Ubuntu:22.04:LTSlinuxno fix listedUBUNTU-CVE-2026-64388
Ubuntu:24.04:LTSlinuxno fix listedUBUNTU-CVE-2026-64388
Ubuntu:26.04:LTSlinux7.0.0-31.31UBUNTU-CVE-2026-64388
Ubuntu:22.04:LTSlinux-allwinner-5.19no fix listedUBUNTU-CVE-2026-64388
Ubuntu:22.04:LTSlinux-awsno fix listedUBUNTU-CVE-2026-64388
Ubuntu:24.04:LTSlinux-awsno fix listedUBUNTU-CVE-2026-64388
Ubuntu:26.04:LTSlinux-aws7.0.0-1012.12UBUNTU-CVE-2026-64388
Ubuntu:22.04:LTSlinux-aws-5.19no fix listedUBUNTU-CVE-2026-64388
Ubuntu:24.04:LTSlinux-aws-6.14no fix listedUBUNTU-CVE-2026-64388
Ubuntu:24.04:LTSlinux-aws-6.17no fix listedUBUNTU-CVE-2026-64388
Ubuntu:22.04:LTSlinux-aws-6.2no fix listedUBUNTU-CVE-2026-64388
Ubuntu:22.04:LTSlinux-aws-6.5no fix listedUBUNTU-CVE-2026-64388
Ubuntu:22.04:LTSlinux-aws-6.8no fix listedUBUNTU-CVE-2026-64388
Ubuntu:24.04:LTSlinux-aws-7.07.0.0-1012.12~24.04.1UBUNTU-CVE-2026-64388
Ubuntu:22.04:LTSlinux-azureno fix listedUBUNTU-CVE-2026-64388
Ubuntu:24.04:LTSlinux-azureno fix listedUBUNTU-CVE-2026-64388
Ubuntu:26.04:LTSlinux-azure7.0.0-1014.14UBUNTU-CVE-2026-64388
Ubuntu:22.04:LTSlinux-azure-5.19no fix listedUBUNTU-CVE-2026-64388
Ubuntu:24.04:LTSlinux-azure-6.11no fix listedUBUNTU-CVE-2026-64388
Ubuntu:24.04:LTSlinux-azure-6.14no fix listedUBUNTU-CVE-2026-64388
Ubuntu:24.04:LTSlinux-azure-6.17no fix listedUBUNTU-CVE-2026-64388
Ubuntu:22.04:LTSlinux-azure-6.2no fix listedUBUNTU-CVE-2026-64388
Ubuntu:22.04:LTSlinux-azure-6.5no fix listedUBUNTU-CVE-2026-64388
Ubuntu:22.04:LTSlinux-azure-6.8no fix listedUBUNTU-CVE-2026-64388
Ubuntu:24.04:LTSlinux-azure-7.07.0.0-1014.14~24.04.1UBUNTU-CVE-2026-64388
Ubuntu:22.04:LTSlinux-azure-fdeno fix listedUBUNTU-CVE-2026-64388
Ubuntu:24.04:LTSlinux-azure-fdeno fix listedUBUNTU-CVE-2026-64388
Ubuntu:26.04:LTSlinux-azure-fde7.0.0-1013.13UBUNTU-CVE-2026-64388
Ubuntu:22.04:LTSlinux-azure-fde-5.19no fix listedUBUNTU-CVE-2026-64388
Ubuntu:24.04:LTSlinux-azure-fde-6.14no fix listedUBUNTU-CVE-2026-64388
Ubuntu:24.04:LTSlinux-azure-fde-6.17no fix listedUBUNTU-CVE-2026-64388
Ubuntu:22.04:LTSlinux-azure-fde-6.2no fix listedUBUNTU-CVE-2026-64388
Ubuntu:22.04:LTSlinux-azure-fde-6.8no fix listedUBUNTU-CVE-2026-64388
Ubuntu:24.04:LTSlinux-azure-fde-7.07.0.0-1013.13~24.04.1UBUNTU-CVE-2026-64388
Ubuntu:24.04:LTSlinux-azure-nvidiano fix listedUBUNTU-CVE-2026-64388
Ubuntu:24.04:LTSlinux-azure-nvidia-6.14no fix listedUBUNTU-CVE-2026-64388
Ubuntu:22.04:LTSlinux-gcpno fix listedUBUNTU-CVE-2026-64388
Ubuntu:24.04:LTSlinux-gcpno fix listedUBUNTU-CVE-2026-64388
Ubuntu:26.04:LTSlinux-gcp7.0.0-1011.11UBUNTU-CVE-2026-64388
Ubuntu:22.04:LTSlinux-gcp-5.19no fix listedUBUNTU-CVE-2026-64388
Ubuntu:24.04:LTSlinux-gcp-6.11no fix listedUBUNTU-CVE-2026-64388
Ubuntu:24.04:LTSlinux-gcp-6.14no fix listedUBUNTU-CVE-2026-64388
Ubuntu:24.04:LTSlinux-gcp-6.17no fix listedUBUNTU-CVE-2026-64388
Ubuntu:22.04:LTSlinux-gcp-6.2no fix listedUBUNTU-CVE-2026-64388
Ubuntu:22.04:LTSlinux-gcp-6.5no fix listedUBUNTU-CVE-2026-64388
Ubuntu:22.04:LTSlinux-gcp-6.8no fix listedUBUNTU-CVE-2026-64388
Ubuntu:24.04:LTSlinux-gcp-7.07.0.0-1011.11~24.04.1UBUNTU-CVE-2026-64388
Ubuntu:22.04:LTSlinux-gkeno fix listedUBUNTU-CVE-2026-64388
Ubuntu:24.04:LTSlinux-gkeno fix listedUBUNTU-CVE-2026-64388
Ubuntu:26.04:LTSlinux-gke7.0.0-1006.7UBUNTU-CVE-2026-64388
Ubuntu:22.04:LTSlinux-gkeopno fix listedUBUNTU-CVE-2026-64388
Ubuntu:24.04:LTSlinux-gkeopno fix listedUBUNTU-CVE-2026-64388
Ubuntu:22.04:LTSlinux-hwe-5.19no fix listedUBUNTU-CVE-2026-64388
Ubuntu:24.04:LTSlinux-hwe-6.11no fix listedUBUNTU-CVE-2026-64388
Ubuntu:24.04:LTSlinux-hwe-6.14no fix listedUBUNTU-CVE-2026-64388
Ubuntu:24.04:LTSlinux-hwe-6.17no fix listedUBUNTU-CVE-2026-64388
Ubuntu:22.04:LTSlinux-hwe-6.2no fix listedUBUNTU-CVE-2026-64388
Ubuntu:22.04:LTSlinux-hwe-6.5no fix listedUBUNTU-CVE-2026-64388
Ubuntu:22.04:LTSlinux-hwe-6.8no fix listedUBUNTU-CVE-2026-64388
Ubuntu:24.04:LTSlinux-hwe-7.07.0.0-31.31~24.04.1UBUNTU-CVE-2026-64388
Ubuntu:22.04:LTSlinux-ibmno fix listedUBUNTU-CVE-2026-64388
Ubuntu:24.04:LTSlinux-ibmno fix listedUBUNTU-CVE-2026-64388
Ubuntu:26.04:LTSlinux-ibm7.0.0-1013.13UBUNTU-CVE-2026-64388
Ubuntu:22.04:LTSlinux-ibm-6.8no fix listedUBUNTU-CVE-2026-64388
Ubuntu:22.04:LTSlinux-intel-iot-realtimeno fix listedUBUNTU-CVE-2026-64388
Ubuntu:22.04:LTSlinux-intel-iotgno fix listedUBUNTU-CVE-2026-64388
Ubuntu:22.04:LTSlinux-kvmno fix listedUBUNTU-CVE-2026-64388
Ubuntu:22.04:LTSlinux-lowlatencyno fix listedUBUNTU-CVE-2026-64388
Ubuntu:24.04:LTSlinux-lowlatencyno fix listedUBUNTU-CVE-2026-64388
Ubuntu:22.04:LTSlinux-lowlatency-hwe-5.19no fix listedUBUNTU-CVE-2026-64388
Ubuntu:24.04:LTSlinux-lowlatency-hwe-6.11no fix listedUBUNTU-CVE-2026-64388
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.2no fix listedUBUNTU-CVE-2026-64388
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.5no fix listedUBUNTU-CVE-2026-64388
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.8no fix listedUBUNTU-CVE-2026-64388
Ubuntu:22.04:LTSlinux-nvidiano fix listedUBUNTU-CVE-2026-64388
Ubuntu:24.04:LTSlinux-nvidiano fix listedUBUNTU-CVE-2026-64388
Ubuntu:26.04:LTSlinux-nvidia7.0.0-1018.18UBUNTU-CVE-2026-64388
Ubuntu:24.04:LTSlinux-nvidia-6.11no fix listedUBUNTU-CVE-2026-64388
Ubuntu:24.04:LTSlinux-nvidia-6.17no fix listedUBUNTU-CVE-2026-64388
Ubuntu:22.04:LTSlinux-nvidia-6.2no fix listedUBUNTU-CVE-2026-64388
Ubuntu:22.04:LTSlinux-nvidia-6.5no fix listedUBUNTU-CVE-2026-64388
Ubuntu:22.04:LTSlinux-nvidia-6.8no fix listedUBUNTU-CVE-2026-64388
Ubuntu:24.04:LTSlinux-nvidia-7.07.0.0-1018.18~24.04.1UBUNTU-CVE-2026-64388
Ubuntu:26.04:LTSlinux-nvidia-bos7.0.0-2018.18UBUNTU-CVE-2026-64388
Ubuntu:24.04:LTSlinux-nvidia-lowlatencyno fix listedUBUNTU-CVE-2026-64388
Ubuntu:22.04:LTSlinux-nvidia-tegrano fix listedUBUNTU-CVE-2026-64388
Ubuntu:24.04:LTSlinux-nvidia-tegra6.8.0-1036.39UBUNTU-CVE-2026-64388
Ubuntu:22.04:LTSlinux-nvidia-tegra-igxno fix listedUBUNTU-CVE-2026-64388
Ubuntu:22.04:LTSlinux-oem-5.17no fix listedUBUNTU-CVE-2026-64388
Ubuntu:22.04:LTSlinux-oem-6.0no fix listedUBUNTU-CVE-2026-64388
Ubuntu:22.04:LTSlinux-oem-6.1no fix listedUBUNTU-CVE-2026-64388
Ubuntu:24.04:LTSlinux-oem-6.11no fix listedUBUNTU-CVE-2026-64388
Ubuntu:24.04:LTSlinux-oem-6.14no fix listedUBUNTU-CVE-2026-64388
Ubuntu:24.04:LTSlinux-oem-6.17no fix listedUBUNTU-CVE-2026-64388
Ubuntu:22.04:LTSlinux-oem-6.5no fix listedUBUNTU-CVE-2026-64388
Ubuntu:24.04:LTSlinux-oem-6.8no fix listedUBUNTU-CVE-2026-64388
Ubuntu:26.04:LTSlinux-oem-7.07.0.0-1013.13UBUNTU-CVE-2026-64388
Ubuntu:22.04:LTSlinux-oracleno fix listedUBUNTU-CVE-2026-64388
Ubuntu:24.04:LTSlinux-oracleno fix listedUBUNTU-CVE-2026-64388
Ubuntu:26.04:LTSlinux-oracle7.0.0-1011.11UBUNTU-CVE-2026-64388
Ubuntu:24.04:LTSlinux-oracle-6.14no fix listedUBUNTU-CVE-2026-64388
Ubuntu:24.04:LTSlinux-oracle-6.17no fix listedUBUNTU-CVE-2026-64388
Ubuntu:22.04:LTSlinux-oracle-6.5no fix listedUBUNTU-CVE-2026-64388
Ubuntu:22.04:LTSlinux-oracle-6.8no fix listedUBUNTU-CVE-2026-64388
Ubuntu:24.04:LTSlinux-oracle-7.07.0.0-1011.11~24.04.1UBUNTU-CVE-2026-64388
Ubuntu:22.04:LTSlinux-raspino fix listedUBUNTU-CVE-2026-64388
Ubuntu:24.04:LTSlinux-raspino fix listedUBUNTU-CVE-2026-64388
Ubuntu:26.04:LTSlinux-raspi7.0.0-1019.19UBUNTU-CVE-2026-64388
Ubuntu:24.04:LTSlinux-raspi-realtimeno fix listedUBUNTU-CVE-2026-64388
Ubuntu:22.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-64388
Ubuntu:24.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-64388
Ubuntu:26.04:LTSlinux-realtime7.0.0-31.31.1UBUNTU-CVE-2026-64388
Ubuntu:22.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2026-64388
Ubuntu:24.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2026-64388
Ubuntu:26.04:LTSlinux-riscv7.0.0-31.31.1UBUNTU-CVE-2026-64388
Ubuntu:22.04:LTSlinux-riscv-5.19no fix listedUBUNTU-CVE-2026-64388
Ubuntu:24.04:LTSlinux-riscv-6.14no fix listedUBUNTU-CVE-2026-64388
Ubuntu:24.04:LTSlinux-riscv-6.17no fix listedUBUNTU-CVE-2026-64388
Ubuntu:22.04:LTSlinux-riscv-6.5no fix listedUBUNTU-CVE-2026-64388
Ubuntu:22.04:LTSlinux-riscv-6.8no fix listedUBUNTU-CVE-2026-64388
Ubuntu:24.04:LTSlinux-riscv-7.07.0.0-31.31.1~24.04.1UBUNTU-CVE-2026-64388
Ubuntu:22.04:LTSlinux-starfive-5.19no fix listedUBUNTU-CVE-2026-64388
Ubuntu:22.04:LTSlinux-starfive-6.2no fix listedUBUNTU-CVE-2026-64388
Ubuntu:22.04:LTSlinux-starfive-6.5no fix listedUBUNTU-CVE-2026-64388
Ubuntu:24.04:LTSlinux-vmwareno fix listedUBUNTU-CVE-2026-64388
Ubuntu:24.04:LTSlinux-xilinxno fix listedUBUNTU-CVE-2026-64388
Ubuntu:22.04:LTSlinux-xilinx-zynqmpno fix listedUBUNTU-CVE-2026-64388

Affected products (as reported)

VendorProductVersions
Linux Linux b326614ea2159ea5c835d320f261d05d080cd201 – before c0fe1118a1471d459f76c3e70ff2abbf784ce6bfb326614ea2159ea5c835d320f261d05d080cd201 – before 6825a45f6b8ef76b0ee32649ec3d6e39ca143a18b326614ea2159ea5c835d320f261d05d080cd201 – before 27ead8c5418af6bfab711079fecb9414d78d4caeb326614ea2159ea5c835d320f261d05d080cd201 – before 3eaec47518e126e6dcd1a48521d740278073f0ecb326614ea2159ea5c835d320f261d05d080cd201 – before 550cfb8a81181331d4d0f76ab75ee58a0bf41e3eb326614ea2159ea5c835d320f261d05d080cd201 – before 760ef2c579c2609cf17fb1cd5392f64d42d43d33
Linux Linux 4.18

Weakness: CWE-682 · Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

References