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Vulnerability · Published Apr 22, 2026 · Assigned by Linux

CVE-2026-31476ksmbd: do not expire session on binding failure

High 8.2

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 0.5% (higher than 43% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)8.2High
Exploit odds (30 days)0.5%top 57.0% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known

Official description

In the Linux kernel, the following vulnerability has been resolved: ksmbd: do not expire session on binding failure When a multichannel session binding request fails (e.g. wrong password), the error path unconditionally sets sess->state = SMB2_SESSION_EXPIRED. However, during binding, sess points to the target session looked up via ksmbd_session_lookup_slowpath() -- which belongs to another connection's user. This allows a remote attacker to invalidate any active session by simply sending a binding request with a wrong password (DoS). Fix this by skipping session expiration when the failed request was a binding attempt, since the session does not belong to the current connection. The reference taken by ksmbd_session_lookup_slowpath() is still correctly released via ksmbd_user_session_put().

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12linux6.1.170-1DEBIAN-CVE-2026-31476
Debian:13linux6.12.85-1DEBIAN-CVE-2026-31476
Debian:14linux6.19.11-1DEBIAN-CVE-2026-31476
Ubuntu:22.04:LTSlinux5.15.0-186.196UBUNTU-CVE-2026-31476
Ubuntu:24.04:LTSlinux6.8.0-136.136UBUNTU-CVE-2026-31476
Ubuntu:25.10linuxno fix listedUBUNTU-CVE-2026-31476
Ubuntu:22.04:LTSlinux-allwinner-5.19no fix listedUBUNTU-CVE-2026-31476
Ubuntu:22.04:LTSlinux-aws5.15.0-1112.119UBUNTU-CVE-2026-31476
Ubuntu:24.04:LTSlinux-aws6.8.0-1061.64UBUNTU-CVE-2026-31476
Ubuntu:25.10linux-awsno fix listedUBUNTU-CVE-2026-31476
Ubuntu:22.04:LTSlinux-aws-5.19no fix listedUBUNTU-CVE-2026-31476
Ubuntu:24.04:LTSlinux-aws-6.14no fix listedUBUNTU-CVE-2026-31476
Ubuntu:24.04:LTSlinux-aws-6.17no fix listedUBUNTU-CVE-2026-31476
Ubuntu:22.04:LTSlinux-aws-6.2no fix listedUBUNTU-CVE-2026-31476
Ubuntu:22.04:LTSlinux-aws-6.5no fix listedUBUNTU-CVE-2026-31476
Ubuntu:22.04:LTSlinux-aws-6.86.8.0-1061.64~22.04.1UBUNTU-CVE-2026-31476
Ubuntu:22.04:LTSlinux-azure5.15.0-1117.126UBUNTU-CVE-2026-31476
Ubuntu:24.04:LTSlinux-azure6.8.0-1063.71UBUNTU-CVE-2026-31476
Ubuntu:25.10linux-azureno fix listedUBUNTU-CVE-2026-31476
Ubuntu:22.04:LTSlinux-azure-5.19no fix listedUBUNTU-CVE-2026-31476
Ubuntu:24.04:LTSlinux-azure-6.11no fix listedUBUNTU-CVE-2026-31476
Ubuntu:24.04:LTSlinux-azure-6.14no fix listedUBUNTU-CVE-2026-31476
Ubuntu:24.04:LTSlinux-azure-6.17no fix listedUBUNTU-CVE-2026-31476
Ubuntu:22.04:LTSlinux-azure-6.2no fix listedUBUNTU-CVE-2026-31476
Ubuntu:22.04:LTSlinux-azure-6.5no fix listedUBUNTU-CVE-2026-31476
Ubuntu:22.04:LTSlinux-azure-6.86.8.0-1063.71~22.04.1UBUNTU-CVE-2026-31476
Ubuntu:22.04:LTSlinux-azure-fde5.15.0-1117.126UBUNTU-CVE-2026-31476
Ubuntu:24.04:LTSlinux-azure-fde6.8.0-1062.69UBUNTU-CVE-2026-31476
Ubuntu:25.10linux-azure-fdeno fix listedUBUNTU-CVE-2026-31476
Ubuntu:22.04:LTSlinux-azure-fde-5.19no fix listedUBUNTU-CVE-2026-31476
Ubuntu:24.04:LTSlinux-azure-fde-6.14no fix listedUBUNTU-CVE-2026-31476
Ubuntu:22.04:LTSlinux-azure-fde-6.2no fix listedUBUNTU-CVE-2026-31476
Ubuntu:22.04:LTSlinux-azure-fde-6.86.8.0-1062.69~22.04.1UBUNTU-CVE-2026-31476
Ubuntu:24.04:LTSlinux-azure-nvidiano fix listedUBUNTU-CVE-2026-31476
Ubuntu:24.04:LTSlinux-azure-nvidia-6.14no fix listedUBUNTU-CVE-2026-31476
Ubuntu:22.04:LTSlinux-gcp5.15.0-1112.122UBUNTU-CVE-2026-31476
Ubuntu:24.04:LTSlinux-gcp6.8.0-1064.72UBUNTU-CVE-2026-31476
Ubuntu:25.10linux-gcpno fix listedUBUNTU-CVE-2026-31476
Ubuntu:22.04:LTSlinux-gcp-5.19no fix listedUBUNTU-CVE-2026-31476
Ubuntu:24.04:LTSlinux-gcp-6.11no fix listedUBUNTU-CVE-2026-31476
Ubuntu:24.04:LTSlinux-gcp-6.14no fix listedUBUNTU-CVE-2026-31476
Ubuntu:24.04:LTSlinux-gcp-6.17no fix listedUBUNTU-CVE-2026-31476
Ubuntu:22.04:LTSlinux-gcp-6.2no fix listedUBUNTU-CVE-2026-31476
Ubuntu:22.04:LTSlinux-gcp-6.5no fix listedUBUNTU-CVE-2026-31476
Ubuntu:22.04:LTSlinux-gcp-6.86.8.0-1064.72~22.04.1UBUNTU-CVE-2026-31476
Ubuntu:22.04:LTSlinux-gke5.15.0-1108.114UBUNTU-CVE-2026-31476
Ubuntu:24.04:LTSlinux-gke6.8.0-1059.67UBUNTU-CVE-2026-31476
Ubuntu:22.04:LTSlinux-gkeop5.15.0-1095.103UBUNTU-CVE-2026-31476
Ubuntu:24.04:LTSlinux-gkeop6.8.0-1046.50UBUNTU-CVE-2026-31476
Ubuntu:22.04:LTSlinux-hwe-5.19no fix listedUBUNTU-CVE-2026-31476
Ubuntu:24.04:LTSlinux-hwe-6.11no fix listedUBUNTU-CVE-2026-31476
Ubuntu:24.04:LTSlinux-hwe-6.14no fix listedUBUNTU-CVE-2026-31476
Ubuntu:24.04:LTSlinux-hwe-6.17no fix listedUBUNTU-CVE-2026-31476
Ubuntu:22.04:LTSlinux-hwe-6.2no fix listedUBUNTU-CVE-2026-31476
Ubuntu:22.04:LTSlinux-hwe-6.5no fix listedUBUNTU-CVE-2026-31476
Ubuntu:22.04:LTSlinux-hwe-6.86.8.0-136.136~22.04.1UBUNTU-CVE-2026-31476
Ubuntu:22.04:LTSlinux-ibm5.15.0-1106.110UBUNTU-CVE-2026-31476
Ubuntu:24.04:LTSlinux-ibm6.8.0-1061.62UBUNTU-CVE-2026-31476
Ubuntu:22.04:LTSlinux-ibm-6.86.8.0-1061.62~22.04.1UBUNTU-CVE-2026-31476
Ubuntu:22.04:LTSlinux-intel-iot-realtimeno fix listedUBUNTU-CVE-2026-31476
Ubuntu:22.04:LTSlinux-intel-iotg5.15.0-1107.113UBUNTU-CVE-2026-31476
Ubuntu:22.04:LTSlinux-kvm5.15.0-1104.109UBUNTU-CVE-2026-31476
Ubuntu:22.04:LTSlinux-lowlatency5.15.0-184.194UBUNTU-CVE-2026-31476
Ubuntu:24.04:LTSlinux-lowlatency6.8.0-136.136.2UBUNTU-CVE-2026-31476
Ubuntu:22.04:LTSlinux-lowlatency-hwe-5.19no fix listedUBUNTU-CVE-2026-31476
Ubuntu:24.04:LTSlinux-lowlatency-hwe-6.11no fix listedUBUNTU-CVE-2026-31476
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.2no fix listedUBUNTU-CVE-2026-31476
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.5no fix listedUBUNTU-CVE-2026-31476
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.86.8.0-136.136.2~22.04.1UBUNTU-CVE-2026-31476
Ubuntu:22.04:LTSlinux-nvidia5.15.0-1107.108UBUNTU-CVE-2026-31476
Ubuntu:24.04:LTSlinux-nvidia6.8.0-1059.62UBUNTU-CVE-2026-31476
Ubuntu:24.04:LTSlinux-nvidia-6.11no fix listedUBUNTU-CVE-2026-31476
Ubuntu:24.04:LTSlinux-nvidia-6.17no fix listedUBUNTU-CVE-2026-31476
Ubuntu:22.04:LTSlinux-nvidia-6.2no fix listedUBUNTU-CVE-2026-31476
Ubuntu:22.04:LTSlinux-nvidia-6.5no fix listedUBUNTU-CVE-2026-31476
Ubuntu:22.04:LTSlinux-nvidia-6.86.8.0-1059.62~22.04.1UBUNTU-CVE-2026-31476
Ubuntu:24.04:LTSlinux-nvidia-lowlatency6.8.0-1059.62.1UBUNTU-CVE-2026-31476
Ubuntu:22.04:LTSlinux-nvidia-tegra5.15.0-1064.66UBUNTU-CVE-2026-31476
Ubuntu:24.04:LTSlinux-nvidia-tegra6.8.0-1030.31UBUNTU-CVE-2026-31476
Ubuntu:22.04:LTSlinux-nvidia-tegra-igx5.15.0-1053.53UBUNTU-CVE-2026-31476
Ubuntu:22.04:LTSlinux-oem-5.17no fix listedUBUNTU-CVE-2026-31476
Ubuntu:22.04:LTSlinux-oem-6.0no fix listedUBUNTU-CVE-2026-31476
Ubuntu:22.04:LTSlinux-oem-6.1no fix listedUBUNTU-CVE-2026-31476
Ubuntu:24.04:LTSlinux-oem-6.11no fix listedUBUNTU-CVE-2026-31476
Ubuntu:24.04:LTSlinux-oem-6.14no fix listedUBUNTU-CVE-2026-31476
Ubuntu:24.04:LTSlinux-oem-6.17no fix listedUBUNTU-CVE-2026-31476
Ubuntu:22.04:LTSlinux-oem-6.5no fix listedUBUNTU-CVE-2026-31476
Ubuntu:24.04:LTSlinux-oem-6.8no fix listedUBUNTU-CVE-2026-31476
Ubuntu:22.04:LTSlinux-oracle5.15.0-1109.115UBUNTU-CVE-2026-31476
Ubuntu:24.04:LTSlinux-oracle6.8.0-1058.61UBUNTU-CVE-2026-31476
Ubuntu:25.10linux-oracleno fix listedUBUNTU-CVE-2026-31476
Ubuntu:24.04:LTSlinux-oracle-6.14no fix listedUBUNTU-CVE-2026-31476
Ubuntu:24.04:LTSlinux-oracle-6.17no fix listedUBUNTU-CVE-2026-31476
Ubuntu:22.04:LTSlinux-oracle-6.5no fix listedUBUNTU-CVE-2026-31476
Ubuntu:22.04:LTSlinux-oracle-6.86.8.0-1058.61~22.04.1UBUNTU-CVE-2026-31476
Ubuntu:22.04:LTSlinux-raspi5.15.0-1106.109UBUNTU-CVE-2026-31476
Ubuntu:24.04:LTSlinux-raspi6.8.0-1061.65UBUNTU-CVE-2026-31476
Ubuntu:25.10linux-raspino fix listedUBUNTU-CVE-2026-31476
Ubuntu:24.04:LTSlinux-raspi-realtimeno fix listedUBUNTU-CVE-2026-31476
Ubuntu:22.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-31476
Ubuntu:24.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-31476
Ubuntu:25.10linux-realtimeno fix listedUBUNTU-CVE-2026-31476
Ubuntu:22.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2026-31476
Ubuntu:24.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2026-31476
Ubuntu:25.10linux-riscvno fix listedUBUNTU-CVE-2026-31476
Ubuntu:22.04:LTSlinux-riscv-5.19no fix listedUBUNTU-CVE-2026-31476
Ubuntu:24.04:LTSlinux-riscv-6.14no fix listedUBUNTU-CVE-2026-31476
Ubuntu:24.04:LTSlinux-riscv-6.17no fix listedUBUNTU-CVE-2026-31476
Ubuntu:22.04:LTSlinux-riscv-6.5no fix listedUBUNTU-CVE-2026-31476
Ubuntu:22.04:LTSlinux-riscv-6.86.8.0-136.136~22.04.3UBUNTU-CVE-2026-31476
Ubuntu:22.04:LTSlinux-starfive-5.19no fix listedUBUNTU-CVE-2026-31476
Ubuntu:22.04:LTSlinux-starfive-6.2no fix listedUBUNTU-CVE-2026-31476
Ubuntu:22.04:LTSlinux-starfive-6.5no fix listedUBUNTU-CVE-2026-31476
Ubuntu:24.04:LTSlinux-vmware6.8.0-1008.8UBUNTU-CVE-2026-31476
Ubuntu:24.04:LTSlinux-xilinx6.8.0-1033.34UBUNTU-CVE-2026-31476
Ubuntu:22.04:LTSlinux-xilinx-zynqmp5.15.0-1075.79UBUNTU-CVE-2026-31476

Affected products (as reported)

VendorProductVersions
Linux Linux f5a544e3bab78142207e0242d22442db85ba1eff – before 4642ea35c03cf3d3558c009df4757cdb7af3f82df5a544e3bab78142207e0242d22442db85ba1eff – before f5300690c23c5ac860499bb37dbc09cf43fd62e6f5a544e3bab78142207e0242d22442db85ba1eff – before 6fafc4c4238e538969f1375f9ecdc6587c53f1ccf5a544e3bab78142207e0242d22442db85ba1eff – before 1d1888b4a7aec518b707f6eca0bf08992c0e8da3f5a544e3bab78142207e0242d22442db85ba1eff – before a897064a457056acb976e20e3007cdf553de340ff5a544e3bab78142207e0242d22442db85ba1eff – before e0e5edc81b241c70355217de7e120c97c3429debf5a544e3bab78142207e0242d22442db85ba1eff – before 9bbb19d21ded7d78645506f20d8c44895e3d0fb9
Linux Linux 5.15

References