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Vulnerability · Published Feb 18, 2026 · Assigned by Linux

CVE-2026-23230smb: client: split cached_fid bitfields to avoid shared-byte RMW races

High 8.8

In plain English

A high-severity race condition 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 0.3% (higher than 20% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)8.8High
Exploit odds (30 days)0.3%top 79.6% 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: split cached_fid bitfields to avoid shared-byte RMW races is_open, has_lease and on_list are stored in the same bitfield byte in struct cached_fid but are updated in different code paths that may run concurrently. Bitfield assignments generate byte read–modify–write operations (e.g. `orb $mask, addr` on x86_64), so updating one flag can restore stale values of the others. A possible interleaving is: CPU1: load old byte (has_lease=1, on_list=1) CPU2: clear both flags (store 0) CPU1: RMW store (old | IS_OPEN) -> reintroduces cleared bits To avoid this class of races, convert these flags to separate bool fields.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12linux6.1.164-1DSA-6163-1
Debian:12linux6.1.164-1DEBIAN-CVE-2026-23230
Debian:13linux6.12.73-1DEBIAN-CVE-2026-23230
Debian:14linux6.18.12-1DEBIAN-CVE-2026-23230
Ubuntu:24.04:LTSlinux6.8.0-134.134UBUNTU-CVE-2026-23230
Ubuntu:24.04:LTSlinux6.8.0-134.134USN-8492-1
Ubuntu:25.10linuxno fix listedUBUNTU-CVE-2026-23230
Ubuntu:22.04:LTSlinux-allwinner-5.19no fix listedUBUNTU-CVE-2026-23230
Ubuntu:24.04:LTSlinux-aws6.8.0-1060.63UBUNTU-CVE-2026-23230
Ubuntu:24.04:LTSlinux-aws6.8.0-1060.63USN-8492-1
Ubuntu:25.10linux-awsno fix listedUBUNTU-CVE-2026-23230
Ubuntu:22.04:LTSlinux-aws-5.19no fix listedUBUNTU-CVE-2026-23230
Ubuntu:24.04:LTSlinux-aws-6.14no fix listedUBUNTU-CVE-2026-23230
Ubuntu:24.04:LTSlinux-aws-6.17no fix listedUBUNTU-CVE-2026-23230
Ubuntu:22.04:LTSlinux-aws-6.2no fix listedUBUNTU-CVE-2026-23230
Ubuntu:22.04:LTSlinux-aws-6.5no fix listedUBUNTU-CVE-2026-23230
Ubuntu:22.04:LTSlinux-aws-6.86.8.0-1060.63~22.04.1UBUNTU-CVE-2026-23230
Ubuntu:22.04:LTSlinux-aws-6.86.8.0-1060.63~22.04.1USN-8492-2
Ubuntu:22.04:LTSlinux-azureno fix listedUBUNTU-CVE-2026-23230
Ubuntu:24.04:LTSlinux-azure6.8.0-1063.71UBUNTU-CVE-2026-23230
Ubuntu:25.10linux-azureno fix listedUBUNTU-CVE-2026-23230
Ubuntu:22.04:LTSlinux-azure-5.19no fix listedUBUNTU-CVE-2026-23230
Ubuntu:24.04:LTSlinux-azure-6.11no fix listedUBUNTU-CVE-2026-23230
Ubuntu:24.04:LTSlinux-azure-6.14no fix listedUBUNTU-CVE-2026-23230
Ubuntu:24.04:LTSlinux-azure-6.17no fix listedUBUNTU-CVE-2026-23230
Ubuntu:22.04:LTSlinux-azure-6.2no fix listedUBUNTU-CVE-2026-23230
Ubuntu:22.04:LTSlinux-azure-6.5no fix listedUBUNTU-CVE-2026-23230
Ubuntu:22.04:LTSlinux-azure-6.86.8.0-1063.71~22.04.1UBUNTU-CVE-2026-23230
Ubuntu:22.04:LTSlinux-azure-fdeno fix listedUBUNTU-CVE-2026-23230
Ubuntu:24.04:LTSlinux-azure-fde6.8.0-1062.69UBUNTU-CVE-2026-23230
Ubuntu:25.10linux-azure-fdeno fix listedUBUNTU-CVE-2026-23230
Ubuntu:22.04:LTSlinux-azure-fde-5.19no fix listedUBUNTU-CVE-2026-23230
Ubuntu:24.04:LTSlinux-azure-fde-6.14no fix listedUBUNTU-CVE-2026-23230
Ubuntu:22.04:LTSlinux-azure-fde-6.2no fix listedUBUNTU-CVE-2026-23230
Ubuntu:22.04:LTSlinux-azure-fde-6.86.8.0-1062.69~22.04.1UBUNTU-CVE-2026-23230
Ubuntu:24.04:LTSlinux-azure-nvidiano fix listedUBUNTU-CVE-2026-23230
Ubuntu:24.04:LTSlinux-azure-nvidia-6.14no fix listedUBUNTU-CVE-2026-23230
Ubuntu:24.04:LTSlinux-gcp6.8.0-1063.69USN-8492-1
Ubuntu:24.04:LTSlinux-gcp6.8.0-1063.69UBUNTU-CVE-2026-23230
Ubuntu:25.10linux-gcpno fix listedUBUNTU-CVE-2026-23230
Ubuntu:22.04:LTSlinux-gcp-5.19no fix listedUBUNTU-CVE-2026-23230
Ubuntu:24.04:LTSlinux-gcp-6.11no fix listedUBUNTU-CVE-2026-23230
Ubuntu:24.04:LTSlinux-gcp-6.14no fix listedUBUNTU-CVE-2026-23230
Ubuntu:24.04:LTSlinux-gcp-6.17no fix listedUBUNTU-CVE-2026-23230
Ubuntu:22.04:LTSlinux-gcp-6.2no fix listedUBUNTU-CVE-2026-23230
Ubuntu:22.04:LTSlinux-gcp-6.5no fix listedUBUNTU-CVE-2026-23230
Ubuntu:22.04:LTSlinux-gcp-6.86.8.0-1063.69~22.04.1USN-8492-2
Ubuntu:22.04:LTSlinux-gcp-6.86.8.0-1063.69~22.04.1UBUNTU-CVE-2026-23230
Ubuntu:24.04:LTSlinux-gke6.8.0-1058.64USN-8492-2
Ubuntu:24.04:LTSlinux-gke6.8.0-1058.64UBUNTU-CVE-2026-23230
Ubuntu:24.04:LTSlinux-gkeop6.8.0-1045.48USN-8492-2
Ubuntu:24.04:LTSlinux-gkeop6.8.0-1045.48UBUNTU-CVE-2026-23230
Ubuntu:22.04:LTSlinux-hwe-5.19no fix listedUBUNTU-CVE-2026-23230
Ubuntu:24.04:LTSlinux-hwe-6.11no fix listedUBUNTU-CVE-2026-23230
Ubuntu:24.04:LTSlinux-hwe-6.14no fix listedUBUNTU-CVE-2026-23230
Ubuntu:24.04:LTSlinux-hwe-6.17no fix listedUBUNTU-CVE-2026-23230
Ubuntu:22.04:LTSlinux-hwe-6.2no fix listedUBUNTU-CVE-2026-23230
Ubuntu:22.04:LTSlinux-hwe-6.5no fix listedUBUNTU-CVE-2026-23230
Ubuntu:22.04:LTSlinux-hwe-6.86.8.0-136.136~22.04.1UBUNTU-CVE-2026-23230
Ubuntu:24.04:LTSlinux-ibm6.8.0-1060.61UBUNTU-CVE-2026-23230
Ubuntu:24.04:LTSlinux-ibm6.8.0-1060.61USN-8492-1
Ubuntu:22.04:LTSlinux-ibm-6.86.8.0-1060.61~22.04.1USN-8492-2
Ubuntu:22.04:LTSlinux-ibm-6.86.8.0-1060.61~22.04.1UBUNTU-CVE-2026-23230
Ubuntu:22.04:LTSlinux-intel-iot-realtimeno fix listedUBUNTU-CVE-2026-23230
Ubuntu:24.04:LTSlinux-lowlatency6.8.0-134.134.1USN-8497-1
Ubuntu:24.04:LTSlinux-lowlatency6.8.0-134.134.1UBUNTU-CVE-2026-23230
Ubuntu:22.04:LTSlinux-lowlatency-hwe-5.19no fix listedUBUNTU-CVE-2026-23230
Ubuntu:24.04:LTSlinux-lowlatency-hwe-6.11no fix listedUBUNTU-CVE-2026-23230
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.2no fix listedUBUNTU-CVE-2026-23230
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.5no fix listedUBUNTU-CVE-2026-23230
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.86.8.0-134.134.1~22.04.1USN-8497-1
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.86.8.0-134.134.1~22.04.1UBUNTU-CVE-2026-23230
Ubuntu:24.04:LTSlinux-nvidia6.8.0-1058.61UBUNTU-CVE-2026-23230
Ubuntu:24.04:LTSlinux-nvidia6.8.0-1058.61USN-8492-1
Ubuntu:24.04:LTSlinux-nvidia-6.11no fix listedUBUNTU-CVE-2026-23230
Ubuntu:24.04:LTSlinux-nvidia-6.17no fix listedUBUNTU-CVE-2026-23230
Ubuntu:22.04:LTSlinux-nvidia-6.2no fix listedUBUNTU-CVE-2026-23230
Ubuntu:22.04:LTSlinux-nvidia-6.5no fix listedUBUNTU-CVE-2026-23230
Ubuntu:22.04:LTSlinux-nvidia-6.86.8.0-1058.61~22.04.1USN-8492-1
Ubuntu:22.04:LTSlinux-nvidia-6.86.8.0-1058.61~22.04.1UBUNTU-CVE-2026-23230
Ubuntu:24.04:LTSlinux-nvidia-lowlatency6.8.0-1058.61.1USN-8492-2
Ubuntu:24.04:LTSlinux-nvidia-lowlatency6.8.0-1058.61.1UBUNTU-CVE-2026-23230
Ubuntu:24.04:LTSlinux-nvidia-tegra6.8.0-1029.30USN-8498-1
Ubuntu:24.04:LTSlinux-nvidia-tegra6.8.0-1029.30UBUNTU-CVE-2026-23230
Ubuntu:22.04:LTSlinux-oem-5.17no fix listedUBUNTU-CVE-2026-23230
Ubuntu:22.04:LTSlinux-oem-6.0no fix listedUBUNTU-CVE-2026-23230
Ubuntu:22.04:LTSlinux-oem-6.1no fix listedUBUNTU-CVE-2026-23230
Ubuntu:24.04:LTSlinux-oem-6.11no fix listedUBUNTU-CVE-2026-23230
Ubuntu:24.04:LTSlinux-oem-6.14no fix listedUBUNTU-CVE-2026-23230
Ubuntu:24.04:LTSlinux-oem-6.17no fix listedUBUNTU-CVE-2026-23230
Ubuntu:22.04:LTSlinux-oem-6.5no fix listedUBUNTU-CVE-2026-23230
Ubuntu:24.04:LTSlinux-oem-6.8no fix listedUBUNTU-CVE-2026-23230
Ubuntu:24.04:LTSlinux-oracle6.8.0-1057.58UBUNTU-CVE-2026-23230
Ubuntu:24.04:LTSlinux-oracle6.8.0-1057.58USN-8492-1
Ubuntu:25.10linux-oracleno fix listedUBUNTU-CVE-2026-23230
Ubuntu:24.04:LTSlinux-oracle-6.14no fix listedUBUNTU-CVE-2026-23230
Ubuntu:24.04:LTSlinux-oracle-6.17no fix listedUBUNTU-CVE-2026-23230
Ubuntu:22.04:LTSlinux-oracle-6.5no fix listedUBUNTU-CVE-2026-23230
Ubuntu:22.04:LTSlinux-oracle-6.86.8.0-1057.58~22.04.1USN-8492-2
Ubuntu:22.04:LTSlinux-oracle-6.86.8.0-1057.58~22.04.1UBUNTU-CVE-2026-23230
Ubuntu:24.04:LTSlinux-raspi6.8.0-1060.64USN-8492-4
Ubuntu:24.04:LTSlinux-raspi6.8.0-1060.64UBUNTU-CVE-2026-23230
Ubuntu:25.10linux-raspino fix listedUBUNTU-CVE-2026-23230
Ubuntu:24.04:LTSlinux-raspi-realtimeno fix listedUBUNTU-CVE-2026-23230
Ubuntu:22.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-23230
Ubuntu:24.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-23230
Ubuntu:25.10linux-realtimeno fix listedUBUNTU-CVE-2026-23230
Ubuntu:22.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2026-23230
Ubuntu:24.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2026-23230
Ubuntu:25.10linux-riscvno fix listedUBUNTU-CVE-2026-23230
Ubuntu:22.04:LTSlinux-riscv-5.19no fix listedUBUNTU-CVE-2026-23230
Ubuntu:24.04:LTSlinux-riscv-6.14no fix listedUBUNTU-CVE-2026-23230
Ubuntu:24.04:LTSlinux-riscv-6.17no fix listedUBUNTU-CVE-2026-23230
Ubuntu:22.04:LTSlinux-riscv-6.5no fix listedUBUNTU-CVE-2026-23230
Ubuntu:22.04:LTSlinux-riscv-6.86.8.0-134.134~22.04.1UBUNTU-CVE-2026-23230
Ubuntu:22.04:LTSlinux-starfive-5.19no fix listedUBUNTU-CVE-2026-23230
Ubuntu:22.04:LTSlinux-starfive-6.2no fix listedUBUNTU-CVE-2026-23230
Ubuntu:22.04:LTSlinux-starfive-6.5no fix listedUBUNTU-CVE-2026-23230
Ubuntu:24.04:LTSlinux-xilinx6.8.0-1032.33UBUNTU-CVE-2026-23230

Affected products (as reported)

VendorProductVersions
Linux Linux ebe98f1447bbccf8228335c62d86af02a0ed23f7 – before 569fecc56bfe4df66f05734d67daef887746656bebe98f1447bbccf8228335c62d86af02a0ed23f7 – before 4386f6af8aaedd0c5ad6f659b40cadcc8f423828ebe98f1447bbccf8228335c62d86af02a0ed23f7 – before 3eaa22d688311c708b73f3c68bc6d0c8e3f0f77aebe98f1447bbccf8228335c62d86af02a0ed23f7 – before c4b9edd55987384a1f201d3d07ff71e448d79c1bebe98f1447bbccf8228335c62d86af02a0ed23f7 – before 4cfa4c37dcbcfd70866e856200ed8a2894cac578ebe98f1447bbccf8228335c62d86af02a0ed23f7 – before ec306600d5ba7148c9dbf8f5a8f1f5c1a044a241
Linux Linux 6.1

Weakness: CWE-362 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

References