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Vulnerability · Published Apr 24, 2026 · Assigned by Linux

CVE-2026-31537smb: server: make use of smbdirect_socket.send_io.bcredits

Medium 5.5

In plain English

A medium-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 2% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS NVD)5.5Medium
Exploit odds (30 days)0.1%top 98.1% 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: smb: server: make use of smbdirect_socket.send_io.bcredits It turns out that our code will corrupt the stream of reassabled data transfer messages when we trigger an immendiate (empty) send. In order to fix this we'll have a single 'batch' credit per connection. And code getting that credit is free to use as much messages until remaining_length reaches 0, then the batch credit it given back and the next logical send can happen.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12linuxno fix listedDEBIAN-CVE-2026-31537
Debian:13linuxno fix listedDEBIAN-CVE-2026-31537
Debian:14linux6.18.12-1DEBIAN-CVE-2026-31537
Ubuntu:22.04:LTSlinuxno fix listedUBUNTU-CVE-2026-31537
Ubuntu:24.04:LTSlinuxno fix listedUBUNTU-CVE-2026-31537
Ubuntu:25.10linuxno fix listedUBUNTU-CVE-2026-31537
Ubuntu:22.04:LTSlinux-allwinner-5.19no fix listedUBUNTU-CVE-2026-31537
Ubuntu:22.04:LTSlinux-awsno fix listedUBUNTU-CVE-2026-31537
Ubuntu:24.04:LTSlinux-awsno fix listedUBUNTU-CVE-2026-31537
Ubuntu:25.10linux-awsno fix listedUBUNTU-CVE-2026-31537
Ubuntu:22.04:LTSlinux-aws-5.19no fix listedUBUNTU-CVE-2026-31537
Ubuntu:24.04:LTSlinux-aws-6.14no fix listedUBUNTU-CVE-2026-31537
Ubuntu:24.04:LTSlinux-aws-6.17no fix listedUBUNTU-CVE-2026-31537
Ubuntu:22.04:LTSlinux-aws-6.2no fix listedUBUNTU-CVE-2026-31537
Ubuntu:22.04:LTSlinux-aws-6.5no fix listedUBUNTU-CVE-2026-31537
Ubuntu:22.04:LTSlinux-aws-6.8no fix listedUBUNTU-CVE-2026-31537
Ubuntu:22.04:LTSlinux-azureno fix listedUBUNTU-CVE-2026-31537
Ubuntu:24.04:LTSlinux-azureno fix listedUBUNTU-CVE-2026-31537
Ubuntu:25.10linux-azureno fix listedUBUNTU-CVE-2026-31537
Ubuntu:22.04:LTSlinux-azure-5.19no fix listedUBUNTU-CVE-2026-31537
Ubuntu:24.04:LTSlinux-azure-6.11no fix listedUBUNTU-CVE-2026-31537
Ubuntu:24.04:LTSlinux-azure-6.14no fix listedUBUNTU-CVE-2026-31537
Ubuntu:24.04:LTSlinux-azure-6.17no fix listedUBUNTU-CVE-2026-31537
Ubuntu:22.04:LTSlinux-azure-6.2no fix listedUBUNTU-CVE-2026-31537
Ubuntu:22.04:LTSlinux-azure-6.5no fix listedUBUNTU-CVE-2026-31537
Ubuntu:22.04:LTSlinux-azure-6.8no fix listedUBUNTU-CVE-2026-31537
Ubuntu:22.04:LTSlinux-azure-fdeno fix listedUBUNTU-CVE-2026-31537
Ubuntu:24.04:LTSlinux-azure-fdeno fix listedUBUNTU-CVE-2026-31537
Ubuntu:25.10linux-azure-fdeno fix listedUBUNTU-CVE-2026-31537
Ubuntu:22.04:LTSlinux-azure-fde-5.19no fix listedUBUNTU-CVE-2026-31537
Ubuntu:24.04:LTSlinux-azure-fde-6.14no fix listedUBUNTU-CVE-2026-31537
Ubuntu:24.04:LTSlinux-azure-fde-6.17no fix listedUBUNTU-CVE-2026-31537
Ubuntu:22.04:LTSlinux-azure-fde-6.2no fix listedUBUNTU-CVE-2026-31537
Ubuntu:22.04:LTSlinux-azure-fde-6.8no fix listedUBUNTU-CVE-2026-31537
Ubuntu:24.04:LTSlinux-azure-nvidiano fix listedUBUNTU-CVE-2026-31537
Ubuntu:24.04:LTSlinux-azure-nvidia-6.14no fix listedUBUNTU-CVE-2026-31537
Ubuntu:22.04:LTSlinux-gcpno fix listedUBUNTU-CVE-2026-31537
Ubuntu:24.04:LTSlinux-gcpno fix listedUBUNTU-CVE-2026-31537
Ubuntu:25.10linux-gcpno fix listedUBUNTU-CVE-2026-31537
Ubuntu:22.04:LTSlinux-gcp-5.19no fix listedUBUNTU-CVE-2026-31537
Ubuntu:24.04:LTSlinux-gcp-6.11no fix listedUBUNTU-CVE-2026-31537
Ubuntu:24.04:LTSlinux-gcp-6.14no fix listedUBUNTU-CVE-2026-31537
Ubuntu:24.04:LTSlinux-gcp-6.17no fix listedUBUNTU-CVE-2026-31537
Ubuntu:22.04:LTSlinux-gcp-6.2no fix listedUBUNTU-CVE-2026-31537
Ubuntu:22.04:LTSlinux-gcp-6.5no fix listedUBUNTU-CVE-2026-31537
Ubuntu:22.04:LTSlinux-gcp-6.8no fix listedUBUNTU-CVE-2026-31537
Ubuntu:22.04:LTSlinux-gkeno fix listedUBUNTU-CVE-2026-31537
Ubuntu:24.04:LTSlinux-gkeno fix listedUBUNTU-CVE-2026-31537
Ubuntu:22.04:LTSlinux-gkeopno fix listedUBUNTU-CVE-2026-31537
Ubuntu:24.04:LTSlinux-gkeopno fix listedUBUNTU-CVE-2026-31537
Ubuntu:22.04:LTSlinux-hwe-5.19no fix listedUBUNTU-CVE-2026-31537
Ubuntu:24.04:LTSlinux-hwe-6.11no fix listedUBUNTU-CVE-2026-31537
Ubuntu:24.04:LTSlinux-hwe-6.14no fix listedUBUNTU-CVE-2026-31537
Ubuntu:24.04:LTSlinux-hwe-6.17no fix listedUBUNTU-CVE-2026-31537
Ubuntu:22.04:LTSlinux-hwe-6.2no fix listedUBUNTU-CVE-2026-31537
Ubuntu:22.04:LTSlinux-hwe-6.5no fix listedUBUNTU-CVE-2026-31537
Ubuntu:22.04:LTSlinux-hwe-6.8no fix listedUBUNTU-CVE-2026-31537
Ubuntu:22.04:LTSlinux-ibmno fix listedUBUNTU-CVE-2026-31537
Ubuntu:24.04:LTSlinux-ibmno fix listedUBUNTU-CVE-2026-31537
Ubuntu:22.04:LTSlinux-ibm-6.8no fix listedUBUNTU-CVE-2026-31537
Ubuntu:22.04:LTSlinux-intel-iot-realtimeno fix listedUBUNTU-CVE-2026-31537
Ubuntu:22.04:LTSlinux-intel-iotgno fix listedUBUNTU-CVE-2026-31537
Ubuntu:22.04:LTSlinux-kvmno fix listedUBUNTU-CVE-2026-31537
Ubuntu:22.04:LTSlinux-lowlatencyno fix listedUBUNTU-CVE-2026-31537
Ubuntu:24.04:LTSlinux-lowlatencyno fix listedUBUNTU-CVE-2026-31537
Ubuntu:22.04:LTSlinux-lowlatency-hwe-5.19no fix listedUBUNTU-CVE-2026-31537
Ubuntu:24.04:LTSlinux-lowlatency-hwe-6.11no fix listedUBUNTU-CVE-2026-31537
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.2no fix listedUBUNTU-CVE-2026-31537
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.5no fix listedUBUNTU-CVE-2026-31537
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.8no fix listedUBUNTU-CVE-2026-31537
Ubuntu:22.04:LTSlinux-nvidiano fix listedUBUNTU-CVE-2026-31537
Ubuntu:24.04:LTSlinux-nvidiano fix listedUBUNTU-CVE-2026-31537
Ubuntu:24.04:LTSlinux-nvidia-6.11no fix listedUBUNTU-CVE-2026-31537
Ubuntu:24.04:LTSlinux-nvidia-6.17no fix listedUBUNTU-CVE-2026-31537
Ubuntu:22.04:LTSlinux-nvidia-6.2no fix listedUBUNTU-CVE-2026-31537
Ubuntu:22.04:LTSlinux-nvidia-6.5no fix listedUBUNTU-CVE-2026-31537
Ubuntu:22.04:LTSlinux-nvidia-6.8no fix listedUBUNTU-CVE-2026-31537
Ubuntu:24.04:LTSlinux-nvidia-lowlatencyno fix listedUBUNTU-CVE-2026-31537
Ubuntu:22.04:LTSlinux-nvidia-tegrano fix listedUBUNTU-CVE-2026-31537
Ubuntu:24.04:LTSlinux-nvidia-tegrano fix listedUBUNTU-CVE-2026-31537
Ubuntu:22.04:LTSlinux-nvidia-tegra-igxno fix listedUBUNTU-CVE-2026-31537
Ubuntu:22.04:LTSlinux-oem-5.17no fix listedUBUNTU-CVE-2026-31537
Ubuntu:22.04:LTSlinux-oem-6.0no fix listedUBUNTU-CVE-2026-31537
Ubuntu:22.04:LTSlinux-oem-6.1no fix listedUBUNTU-CVE-2026-31537
Ubuntu:24.04:LTSlinux-oem-6.11no fix listedUBUNTU-CVE-2026-31537
Ubuntu:24.04:LTSlinux-oem-6.14no fix listedUBUNTU-CVE-2026-31537
Ubuntu:24.04:LTSlinux-oem-6.17no fix listedUBUNTU-CVE-2026-31537
Ubuntu:22.04:LTSlinux-oem-6.5no fix listedUBUNTU-CVE-2026-31537
Ubuntu:24.04:LTSlinux-oem-6.8no fix listedUBUNTU-CVE-2026-31537
Ubuntu:22.04:LTSlinux-oracleno fix listedUBUNTU-CVE-2026-31537
Ubuntu:24.04:LTSlinux-oracleno fix listedUBUNTU-CVE-2026-31537
Ubuntu:25.10linux-oracleno fix listedUBUNTU-CVE-2026-31537
Ubuntu:24.04:LTSlinux-oracle-6.14no fix listedUBUNTU-CVE-2026-31537
Ubuntu:24.04:LTSlinux-oracle-6.17no fix listedUBUNTU-CVE-2026-31537
Ubuntu:22.04:LTSlinux-oracle-6.5no fix listedUBUNTU-CVE-2026-31537
Ubuntu:22.04:LTSlinux-oracle-6.8no fix listedUBUNTU-CVE-2026-31537
Ubuntu:22.04:LTSlinux-raspino fix listedUBUNTU-CVE-2026-31537
Ubuntu:24.04:LTSlinux-raspino fix listedUBUNTU-CVE-2026-31537
Ubuntu:25.10linux-raspino fix listedUBUNTU-CVE-2026-31537
Ubuntu:24.04:LTSlinux-raspi-realtimeno fix listedUBUNTU-CVE-2026-31537
Ubuntu:22.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-31537
Ubuntu:24.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-31537
Ubuntu:25.10linux-realtimeno fix listedUBUNTU-CVE-2026-31537
Ubuntu:22.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2026-31537
Ubuntu:24.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2026-31537
Ubuntu:25.10linux-riscvno fix listedUBUNTU-CVE-2026-31537
Ubuntu:22.04:LTSlinux-riscv-5.19no fix listedUBUNTU-CVE-2026-31537
Ubuntu:24.04:LTSlinux-riscv-6.14no fix listedUBUNTU-CVE-2026-31537
Ubuntu:24.04:LTSlinux-riscv-6.17no fix listedUBUNTU-CVE-2026-31537
Ubuntu:22.04:LTSlinux-riscv-6.5no fix listedUBUNTU-CVE-2026-31537
Ubuntu:22.04:LTSlinux-riscv-6.8no fix listedUBUNTU-CVE-2026-31537
Ubuntu:22.04:LTSlinux-starfive-5.19no fix listedUBUNTU-CVE-2026-31537
Ubuntu:22.04:LTSlinux-starfive-6.2no fix listedUBUNTU-CVE-2026-31537
Ubuntu:22.04:LTSlinux-starfive-6.5no fix listedUBUNTU-CVE-2026-31537
Ubuntu:24.04:LTSlinux-vmwareno fix listedUBUNTU-CVE-2026-31537
Ubuntu:24.04:LTSlinux-xilinxno fix listedUBUNTU-CVE-2026-31537
Ubuntu:22.04:LTSlinux-xilinx-zynqmpno fix listedUBUNTU-CVE-2026-31537

Affected products (as reported)

VendorProductVersions
Linux Linux 0626e6641f6b467447c81dd7678a69c66f7746cf – before 5ef18a2e66f2f33fdac64437bddfb9fe6389fdc70626e6641f6b467447c81dd7678a69c66f7746cf – before 79242e7b6bc63efec28b7c235bc320806afce6c00626e6641f6b467447c81dd7678a69c66f7746cf – before 34abd408c8ba24d7c97bd02ba874d8c714f49db1
Linux Linux 5.15

References