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Vulnerability · Published Feb 4, 2026 · Assigned by Linux

CVE-2026-23105net/sched: qfq: Use cl_is_active to determine whether class is active in qfq_rm_from_ag

High 7.8

In plain English

A high-severity improper input validation 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 4% 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 96.2% 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: net/sched: qfq: Use cl_is_active to determine whether class is active in qfq_rm_from_ag This is more of a preventive patch to make the code more consistent and to prevent possible exploits that employ child qlen manipulations on qfq. use cl_is_active instead of relying on the child qdisc's qlen to determine class activation.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
AlmaLinux:8bpftool4.18.0-553.171.1.el8_10ALSA-2026:75747
AlmaLinux:8kernel4.18.0-553.171.1.el8_10ALSA-2026:75747
AlmaLinux:8kernel-abi-stablelists4.18.0-553.171.1.el8_10ALSA-2026:75747
AlmaLinux:8kernel-core4.18.0-553.171.1.el8_10ALSA-2026:75747
AlmaLinux:8kernel-cross-headers4.18.0-553.171.1.el8_10ALSA-2026:75747
AlmaLinux:8kernel-debug4.18.0-553.171.1.el8_10ALSA-2026:75747
AlmaLinux:8kernel-debug-core4.18.0-553.171.1.el8_10ALSA-2026:75747
AlmaLinux:8kernel-debug-devel4.18.0-553.171.1.el8_10ALSA-2026:75747
AlmaLinux:8kernel-debug-modules4.18.0-553.171.1.el8_10ALSA-2026:75747
AlmaLinux:8kernel-debug-modules-extra4.18.0-553.171.1.el8_10ALSA-2026:75747
AlmaLinux:8kernel-devel4.18.0-553.171.1.el8_10ALSA-2026:75747
AlmaLinux:8kernel-doc4.18.0-553.171.1.el8_10ALSA-2026:75747
AlmaLinux:8kernel-headers4.18.0-553.171.1.el8_10ALSA-2026:75747
AlmaLinux:8kernel-modules4.18.0-553.171.1.el8_10ALSA-2026:75747
AlmaLinux:8kernel-modules-extra4.18.0-553.171.1.el8_10ALSA-2026:75747
AlmaLinux:8kernel-rt4.18.0-553.171.1.rt7.512.el8_10ALSA-2026:75746
AlmaLinux:8kernel-rt-core4.18.0-553.171.1.rt7.512.el8_10ALSA-2026:75746
AlmaLinux:8kernel-rt-debug4.18.0-553.171.1.rt7.512.el8_10ALSA-2026:75746
AlmaLinux:8kernel-rt-debug-core4.18.0-553.171.1.rt7.512.el8_10ALSA-2026:75746
AlmaLinux:8kernel-rt-debug-devel4.18.0-553.171.1.rt7.512.el8_10ALSA-2026:75746
AlmaLinux:8kernel-rt-debug-modules4.18.0-553.171.1.rt7.512.el8_10ALSA-2026:75746
AlmaLinux:8kernel-rt-debug-modules-extra4.18.0-553.171.1.rt7.512.el8_10ALSA-2026:75746
AlmaLinux:8kernel-rt-devel4.18.0-553.171.1.rt7.512.el8_10ALSA-2026:75746
AlmaLinux:8kernel-rt-modules4.18.0-553.171.1.rt7.512.el8_10ALSA-2026:75746
AlmaLinux:8kernel-rt-modules-extra4.18.0-553.171.1.rt7.512.el8_10ALSA-2026:75746
AlmaLinux:8kernel-tools4.18.0-553.171.1.el8_10ALSA-2026:75747
AlmaLinux:8kernel-tools-libs4.18.0-553.171.1.el8_10ALSA-2026:75747
AlmaLinux:8kernel-tools-libs-devel4.18.0-553.171.1.el8_10ALSA-2026:75747
AlmaLinux:8kernel-zfcpdump4.18.0-553.171.1.el8_10ALSA-2026:75747
AlmaLinux:8kernel-zfcpdump-core4.18.0-553.171.1.el8_10ALSA-2026:75747
AlmaLinux:8kernel-zfcpdump-devel4.18.0-553.171.1.el8_10ALSA-2026:75747
AlmaLinux:8kernel-zfcpdump-modules4.18.0-553.171.1.el8_10ALSA-2026:75747
AlmaLinux:8kernel-zfcpdump-modules-extra4.18.0-553.171.1.el8_10ALSA-2026:75747
AlmaLinux:8perf4.18.0-553.171.1.el8_10ALSA-2026:75747
AlmaLinux:8python3-perf4.18.0-553.171.1.el8_10ALSA-2026:75747
Debian:12linux6.1.162-1DEBIAN-CVE-2026-23105
Debian:13linux6.12.69-1DEBIAN-CVE-2026-23105
Debian:14linux6.18.8-1DEBIAN-CVE-2026-23105
Rocky Linux:8kernel0:4.18.0-553.171.1.el8_10RLSA-2026:75747
Rocky Linux:8kernel-rt0:4.18.0-553.171.1.rt7.512.el8_10RLSA-2026:75746
Ubuntu:22.04:LTSlinux5.15.0-176.186UBUNTU-CVE-2026-23105
Ubuntu:24.04:LTSlinux6.8.0-117.117UBUNTU-CVE-2026-23105
Ubuntu:25.10linuxno fix listedUBUNTU-CVE-2026-23105
Ubuntu:22.04:LTSlinux-allwinner-5.19no fix listedUBUNTU-CVE-2026-23105
Ubuntu:22.04:LTSlinux-aws5.15.0-1105.112UBUNTU-CVE-2026-23105
Ubuntu:24.04:LTSlinux-aws6.8.0-1055.58UBUNTU-CVE-2026-23105
Ubuntu:25.10linux-awsno fix listedUBUNTU-CVE-2026-23105
Ubuntu:22.04:LTSlinux-aws-5.19no fix listedUBUNTU-CVE-2026-23105
Ubuntu:24.04:LTSlinux-aws-6.14no fix listedUBUNTU-CVE-2026-23105
Ubuntu:24.04:LTSlinux-aws-6.17no fix listedUBUNTU-CVE-2026-23105
Ubuntu:22.04:LTSlinux-aws-6.2no fix listedUBUNTU-CVE-2026-23105
Ubuntu:22.04:LTSlinux-aws-6.5no fix listedUBUNTU-CVE-2026-23105
Ubuntu:22.04:LTSlinux-aws-6.86.8.0-1057.60~22.04.1UBUNTU-CVE-2026-23105
Ubuntu:22.04:LTSlinux-azure5.15.0-1110.119UBUNTU-CVE-2026-23105
Ubuntu:24.04:LTSlinux-azure6.8.0-1056.62UBUNTU-CVE-2026-23105
Ubuntu:25.10linux-azureno fix listedUBUNTU-CVE-2026-23105
Ubuntu:22.04:LTSlinux-azure-5.19no fix listedUBUNTU-CVE-2026-23105
Ubuntu:24.04:LTSlinux-azure-6.11no fix listedUBUNTU-CVE-2026-23105
Ubuntu:24.04:LTSlinux-azure-6.14no fix listedUBUNTU-CVE-2026-23105
Ubuntu:24.04:LTSlinux-azure-6.176.17.0-1021.21~24.04.1UBUNTU-CVE-2026-23105
Ubuntu:22.04:LTSlinux-azure-6.2no fix listedUBUNTU-CVE-2026-23105
Ubuntu:22.04:LTSlinux-azure-6.5no fix listedUBUNTU-CVE-2026-23105
Ubuntu:22.04:LTSlinux-azure-6.86.8.0-1059.65~22.04.1UBUNTU-CVE-2026-23105
Ubuntu:22.04:LTSlinux-azure-fde5.15.0-1114.123UBUNTU-CVE-2026-23105
Ubuntu:24.04:LTSlinux-azure-fde6.8.0-1058.65UBUNTU-CVE-2026-23105
Ubuntu:25.10linux-azure-fdeno fix listedUBUNTU-CVE-2026-23105
Ubuntu:22.04:LTSlinux-azure-fde-5.19no fix listedUBUNTU-CVE-2026-23105
Ubuntu:24.04:LTSlinux-azure-fde-6.14no fix listedUBUNTU-CVE-2026-23105
Ubuntu:22.04:LTSlinux-azure-fde-6.2no fix listedUBUNTU-CVE-2026-23105
Ubuntu:22.04:LTSlinux-azure-fde-6.86.8.0-1058.65~22.04.1UBUNTU-CVE-2026-23105
Ubuntu:24.04:LTSlinux-azure-nvidiano fix listedUBUNTU-CVE-2026-23105
Ubuntu:24.04:LTSlinux-azure-nvidia-6.14no fix listedUBUNTU-CVE-2026-23105
Ubuntu:22.04:LTSlinux-gcp5.15.0-1105.114UBUNTU-CVE-2026-23105
Ubuntu:24.04:LTSlinux-gcp6.8.0-1058.61UBUNTU-CVE-2026-23105
Ubuntu:25.10linux-gcpno fix listedUBUNTU-CVE-2026-23105
Ubuntu:22.04:LTSlinux-gcp-5.19no fix listedUBUNTU-CVE-2026-23105
Ubuntu:24.04:LTSlinux-gcp-6.11no fix listedUBUNTU-CVE-2026-23105
Ubuntu:24.04:LTSlinux-gcp-6.14no fix listedUBUNTU-CVE-2026-23105
Ubuntu:24.04:LTSlinux-gcp-6.176.17.0-1021.24~24.04.1UBUNTU-CVE-2026-23105
Ubuntu:22.04:LTSlinux-gcp-6.2no fix listedUBUNTU-CVE-2026-23105
Ubuntu:22.04:LTSlinux-gcp-6.5no fix listedUBUNTU-CVE-2026-23105
Ubuntu:22.04:LTSlinux-gcp-6.86.8.0-1060.63~22.04.1UBUNTU-CVE-2026-23105
Ubuntu:22.04:LTSlinux-gke5.15.0-1101.107UBUNTU-CVE-2026-23105
Ubuntu:24.04:LTSlinux-gke6.8.0-1054.60UBUNTU-CVE-2026-23105
Ubuntu:22.04:LTSlinux-gkeop5.15.0-1088.96UBUNTU-CVE-2026-23105
Ubuntu:24.04:LTSlinux-gkeop6.8.0-1041.44UBUNTU-CVE-2026-23105
Ubuntu:22.04:LTSlinux-hwe-5.19no fix listedUBUNTU-CVE-2026-23105
Ubuntu:24.04:LTSlinux-hwe-6.11no fix listedUBUNTU-CVE-2026-23105
Ubuntu:24.04:LTSlinux-hwe-6.14no fix listedUBUNTU-CVE-2026-23105
Ubuntu:24.04:LTSlinux-hwe-6.176.17.0-41.41~24.04.1UBUNTU-CVE-2026-23105
Ubuntu:22.04:LTSlinux-hwe-6.2no fix listedUBUNTU-CVE-2026-23105
Ubuntu:22.04:LTSlinux-hwe-6.5no fix listedUBUNTU-CVE-2026-23105
Ubuntu:22.04:LTSlinux-hwe-6.86.8.0-124.124~22.04.1UBUNTU-CVE-2026-23105
Ubuntu:22.04:LTSlinux-ibm5.15.0-1099.102UBUNTU-CVE-2026-23105
Ubuntu:24.04:LTSlinux-ibm6.8.0-1055.56UBUNTU-CVE-2026-23105
Ubuntu:22.04:LTSlinux-ibm-6.86.8.0-1055.56~22.04.1UBUNTU-CVE-2026-23105
Ubuntu:22.04:LTSlinux-intel-iot-realtimeno fix listedUBUNTU-CVE-2026-23105
Ubuntu:22.04:LTSlinux-intel-iotg5.15.0-1100.106UBUNTU-CVE-2026-23105
Ubuntu:22.04:LTSlinux-kvm5.15.0-1097.102UBUNTU-CVE-2026-23105
Ubuntu:22.04:LTSlinux-lowlatency5.15.0-175.185UBUNTU-CVE-2026-23105
Ubuntu:24.04:LTSlinux-lowlatency6.8.0-117.117.1UBUNTU-CVE-2026-23105
Ubuntu:22.04:LTSlinux-lowlatency-hwe-5.19no fix listedUBUNTU-CVE-2026-23105
Ubuntu:24.04:LTSlinux-lowlatency-hwe-6.11no fix listedUBUNTU-CVE-2026-23105
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.2no fix listedUBUNTU-CVE-2026-23105
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.5no fix listedUBUNTU-CVE-2026-23105
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.86.8.0-117.117.1~22.04.1UBUNTU-CVE-2026-23105
Ubuntu:22.04:LTSlinux-nvidia5.15.0-1100.101UBUNTU-CVE-2026-23105
Ubuntu:24.04:LTSlinux-nvidia6.8.0-1054.57UBUNTU-CVE-2026-23105
Ubuntu:24.04:LTSlinux-nvidia-6.11no fix listedUBUNTU-CVE-2026-23105
Ubuntu:24.04:LTSlinux-nvidia-6.176.17.0-1031.31UBUNTU-CVE-2026-23105
Ubuntu:22.04:LTSlinux-nvidia-6.2no fix listedUBUNTU-CVE-2026-23105
Ubuntu:22.04:LTSlinux-nvidia-6.5no fix listedUBUNTU-CVE-2026-23105
Ubuntu:22.04:LTSlinux-nvidia-6.86.8.0-1054.57~22.04.1UBUNTU-CVE-2026-23105
Ubuntu:24.04:LTSlinux-nvidia-lowlatency6.8.0-1054.57.1UBUNTU-CVE-2026-23105
Ubuntu:22.04:LTSlinux-nvidia-tegra5.15.0-1057.57UBUNTU-CVE-2026-23105
Ubuntu:24.04:LTSlinux-nvidia-tegra6.8.0-1024.24UBUNTU-CVE-2026-23105
Ubuntu:22.04:LTSlinux-nvidia-tegra-igx5.15.0-1046.46UBUNTU-CVE-2026-23105
Ubuntu:22.04:LTSlinux-oem-5.17no fix listedUBUNTU-CVE-2026-23105
Ubuntu:22.04:LTSlinux-oem-6.0no fix listedUBUNTU-CVE-2026-23105
Ubuntu:22.04:LTSlinux-oem-6.1no fix listedUBUNTU-CVE-2026-23105
Ubuntu:24.04:LTSlinux-oem-6.11no fix listedUBUNTU-CVE-2026-23105
Ubuntu:24.04:LTSlinux-oem-6.14no fix listedUBUNTU-CVE-2026-23105
Ubuntu:24.04:LTSlinux-oem-6.176.17.0-1030.30UBUNTU-CVE-2026-23105
Ubuntu:22.04:LTSlinux-oem-6.5no fix listedUBUNTU-CVE-2026-23105
Ubuntu:24.04:LTSlinux-oem-6.8no fix listedUBUNTU-CVE-2026-23105
Ubuntu:22.04:LTSlinux-oracle5.15.0-1102.108UBUNTU-CVE-2026-23105
Ubuntu:24.04:LTSlinux-oracle6.8.0-1054.55UBUNTU-CVE-2026-23105
Ubuntu:25.10linux-oracleno fix listedUBUNTU-CVE-2026-23105
Ubuntu:24.04:LTSlinux-oracle-6.14no fix listedUBUNTU-CVE-2026-23105
Ubuntu:24.04:LTSlinux-oracle-6.176.17.0-1019.19~24.04.3UBUNTU-CVE-2026-23105
Ubuntu:22.04:LTSlinux-oracle-6.5no fix listedUBUNTU-CVE-2026-23105
Ubuntu:22.04:LTSlinux-oracle-6.86.8.0-1054.55~22.04.1UBUNTU-CVE-2026-23105
Ubuntu:22.04:LTSlinux-raspi5.15.0-1099.102UBUNTU-CVE-2026-23105
Ubuntu:24.04:LTSlinux-raspi6.8.0-1056.60UBUNTU-CVE-2026-23105
Ubuntu:25.10linux-raspino fix listedUBUNTU-CVE-2026-23105
Ubuntu:24.04:LTSlinux-raspi-realtimeno fix listedUBUNTU-CVE-2026-23105
Ubuntu:22.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-23105
Ubuntu:24.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-23105
Ubuntu:25.10linux-realtimeno fix listedUBUNTU-CVE-2026-23105
Ubuntu:22.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2026-23105
Ubuntu:24.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2026-23105
Ubuntu:25.10linux-riscvno fix listedUBUNTU-CVE-2026-23105
Ubuntu:22.04:LTSlinux-riscv-5.19no fix listedUBUNTU-CVE-2026-23105
Ubuntu:24.04:LTSlinux-riscv-6.14no fix listedUBUNTU-CVE-2026-23105
Ubuntu:24.04:LTSlinux-riscv-6.17no fix listedUBUNTU-CVE-2026-23105
Ubuntu:22.04:LTSlinux-riscv-6.5no fix listedUBUNTU-CVE-2026-23105
Ubuntu:22.04:LTSlinux-riscv-6.86.8.0-117.117~22.04.1UBUNTU-CVE-2026-23105
Ubuntu:22.04:LTSlinux-starfive-5.19no fix listedUBUNTU-CVE-2026-23105
Ubuntu:22.04:LTSlinux-starfive-6.2no fix listedUBUNTU-CVE-2026-23105
Ubuntu:22.04:LTSlinux-starfive-6.5no fix listedUBUNTU-CVE-2026-23105
Ubuntu:24.04:LTSlinux-xilinx6.8.0-1032.33UBUNTU-CVE-2026-23105
Ubuntu:22.04:LTSlinux-xilinx-zynqmp5.15.0-1070.74UBUNTU-CVE-2026-23105

Affected products (as reported)

VendorProductVersions
Linux Linux 462dbc9101acd38e92eda93c0726857517a24bbd – before fac2c67bb2bb732eae4283e45fc338af7e08c254462dbc9101acd38e92eda93c0726857517a24bbd – before b8c24cf5268fb3bfb8d16324c3dbb985f698c835462dbc9101acd38e92eda93c0726857517a24bbd – before f27047abf7cac1b6f90c3ad60de21ef9f717c26d462dbc9101acd38e92eda93c0726857517a24bbd – before 93b8635974fb050c43d07e35e5edfe6e685ca28a462dbc9101acd38e92eda93c0726857517a24bbd – before abd9fc26ea577561a5ef6241a1b058755ffdad0c462dbc9101acd38e92eda93c0726857517a24bbd – before 77f1afd0bb4d5da95236f6114e6d0dfcde187ff6462dbc9101acd38e92eda93c0726857517a24bbd – before d837fbee92453fbb829f950c8e7cf76207d73f33
Linux Linux 3.8

Weakness: CWE-20 · Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

References