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Vulnerability · Published Sep 25, 2026 · Assigned by Linux

CVE-2026-98012net/sched: sfq: clamp quantum in change path

Unrated

In plain English

A 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 0.2% (higher than 7% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS )–Not rated
Exploit odds (30 days)0.2%top 92.7% 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: net/sched: sfq: clamp quantum in change path sfq_change() accepts any non-negative quantum (only rejects (int)ctl->quantum < 0). With a crafted size table qdisc_pkt_len reaches ~2 GiB, so quantum=1 makes the deficit-refill loop spin ~2^31 times under the qdisc lock (a soft lockup / denial of service). Add max(256U, ...) matching fq_codel_change(). Reject quantum > 1<<20 with -EINVAL, matching fq_codel_change() and the init clamp. Conditions to recreate the bug: CONFIG_NET_SCH_SFQ=y. Requires CAP_NET_ADMIN (namespace-local via unshare -Urn suffices). tc qdisc add dev dummy0 root sfq tc qdisc change dev dummy0 root sfq quantum 1 stab data 32768 size_log 15 cell_log 0

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12linux6.1.190-1DEBIAN-CVE-2026-98012
Debian:13linux6.12.111-1DEBIAN-CVE-2026-98012
Debian:14linux7.2.7-1DEBIAN-CVE-2026-98012
Debian:12linux-6.126.12.111-1~deb12u1DEBIAN-CVE-2026-98012
Ubuntu:22.04:LTSlinux5.15.0-202.212UBUNTU-CVE-2026-98012
Ubuntu:24.04:LTSlinuxno fix listedUBUNTU-CVE-2026-98012
Ubuntu:26.04:LTSlinux7.0.0-42.42UBUNTU-CVE-2026-98012
Ubuntu:22.04:LTSlinux-allwinner-5.19no fix listedUBUNTU-CVE-2026-98012
Ubuntu:22.04:LTSlinux-aws5.15.0-1119.126UBUNTU-CVE-2026-98012
Ubuntu:24.04:LTSlinux-awsno fix listedUBUNTU-CVE-2026-98012
Ubuntu:26.04:LTSlinux-aws7.0.0-1016.17UBUNTU-CVE-2026-98012
Ubuntu:22.04:LTSlinux-aws-5.19no fix listedUBUNTU-CVE-2026-98012
Ubuntu:24.04:LTSlinux-aws-6.14no fix listedUBUNTU-CVE-2026-98012
Ubuntu:24.04:LTSlinux-aws-6.17no fix listedUBUNTU-CVE-2026-98012
Ubuntu:22.04:LTSlinux-aws-6.2no fix listedUBUNTU-CVE-2026-98012
Ubuntu:22.04:LTSlinux-aws-6.5no fix listedUBUNTU-CVE-2026-98012
Ubuntu:22.04:LTSlinux-aws-6.8no fix listedUBUNTU-CVE-2026-98012
Ubuntu:24.04:LTSlinux-aws-7.0no fix listedUBUNTU-CVE-2026-98012
Ubuntu:22.04:LTSlinux-azure5.15.0-1125.134UBUNTU-CVE-2026-98012
Ubuntu:24.04:LTSlinux-azureno fix listedUBUNTU-CVE-2026-98012
Ubuntu:26.04:LTSlinux-azureno fix listedUBUNTU-CVE-2026-98012
Ubuntu:22.04:LTSlinux-azure-5.19no fix listedUBUNTU-CVE-2026-98012
Ubuntu:24.04:LTSlinux-azure-6.11no fix listedUBUNTU-CVE-2026-98012
Ubuntu:24.04:LTSlinux-azure-6.14no fix listedUBUNTU-CVE-2026-98012
Ubuntu:24.04:LTSlinux-azure-6.17no fix listedUBUNTU-CVE-2026-98012
Ubuntu:22.04:LTSlinux-azure-6.2no fix listedUBUNTU-CVE-2026-98012
Ubuntu:22.04:LTSlinux-azure-6.5no fix listedUBUNTU-CVE-2026-98012
Ubuntu:22.04:LTSlinux-azure-6.8no fix listedUBUNTU-CVE-2026-98012
Ubuntu:24.04:LTSlinux-azure-7.0no fix listedUBUNTU-CVE-2026-98012
Ubuntu:22.04:LTSlinux-azure-fde5.15.0-1124.133UBUNTU-CVE-2026-98012
Ubuntu:24.04:LTSlinux-azure-fdeno fix listedUBUNTU-CVE-2026-98012
Ubuntu:26.04:LTSlinux-azure-fdeno fix listedUBUNTU-CVE-2026-98012
Ubuntu:22.04:LTSlinux-azure-fde-5.19no fix listedUBUNTU-CVE-2026-98012
Ubuntu:24.04:LTSlinux-azure-fde-6.14no fix listedUBUNTU-CVE-2026-98012
Ubuntu:24.04:LTSlinux-azure-fde-6.17no fix listedUBUNTU-CVE-2026-98012
Ubuntu:22.04:LTSlinux-azure-fde-6.2no fix listedUBUNTU-CVE-2026-98012
Ubuntu:22.04:LTSlinux-azure-fde-6.8no fix listedUBUNTU-CVE-2026-98012
Ubuntu:24.04:LTSlinux-azure-fde-7.0no fix listedUBUNTU-CVE-2026-98012
Ubuntu:24.04:LTSlinux-azure-nvidiano fix listedUBUNTU-CVE-2026-98012
Ubuntu:24.04:LTSlinux-azure-nvidia-6.14no fix listedUBUNTU-CVE-2026-98012
Ubuntu:22.04:LTSlinux-gcp5.15.0-1120.130UBUNTU-CVE-2026-98012
Ubuntu:24.04:LTSlinux-gcpno fix listedUBUNTU-CVE-2026-98012
Ubuntu:26.04:LTSlinux-gcp7.0.0-1016.18UBUNTU-CVE-2026-98012
Ubuntu:22.04:LTSlinux-gcp-5.19no fix listedUBUNTU-CVE-2026-98012
Ubuntu:24.04:LTSlinux-gcp-6.11no fix listedUBUNTU-CVE-2026-98012
Ubuntu:24.04:LTSlinux-gcp-6.14no fix listedUBUNTU-CVE-2026-98012
Ubuntu:24.04:LTSlinux-gcp-6.17no fix listedUBUNTU-CVE-2026-98012
Ubuntu:22.04:LTSlinux-gcp-6.2no fix listedUBUNTU-CVE-2026-98012
Ubuntu:22.04:LTSlinux-gcp-6.5no fix listedUBUNTU-CVE-2026-98012
Ubuntu:22.04:LTSlinux-gcp-6.8no fix listedUBUNTU-CVE-2026-98012
Ubuntu:24.04:LTSlinux-gcp-7.0no fix listedUBUNTU-CVE-2026-98012
Ubuntu:22.04:LTSlinux-gke5.15.0-1115.121UBUNTU-CVE-2026-98012
Ubuntu:24.04:LTSlinux-gkeno fix listedUBUNTU-CVE-2026-98012
Ubuntu:26.04:LTSlinux-gkeno fix listedUBUNTU-CVE-2026-98012
Ubuntu:22.04:LTSlinux-gkeop5.15.0-1102.110UBUNTU-CVE-2026-98012
Ubuntu:24.04:LTSlinux-gkeopno fix listedUBUNTU-CVE-2026-98012
Ubuntu:22.04:LTSlinux-hwe-5.19no fix listedUBUNTU-CVE-2026-98012
Ubuntu:24.04:LTSlinux-hwe-6.11no fix listedUBUNTU-CVE-2026-98012
Ubuntu:24.04:LTSlinux-hwe-6.14no fix listedUBUNTU-CVE-2026-98012
Ubuntu:24.04:LTSlinux-hwe-6.17no fix listedUBUNTU-CVE-2026-98012
Ubuntu:22.04:LTSlinux-hwe-6.2no fix listedUBUNTU-CVE-2026-98012
Ubuntu:22.04:LTSlinux-hwe-6.5no fix listedUBUNTU-CVE-2026-98012
Ubuntu:22.04:LTSlinux-hwe-6.8no fix listedUBUNTU-CVE-2026-98012
Ubuntu:24.04:LTSlinux-hwe-7.07.0.0-42.42~24.04.1UBUNTU-CVE-2026-98012
Ubuntu:22.04:LTSlinux-ibm5.15.0-1113.117UBUNTU-CVE-2026-98012
Ubuntu:24.04:LTSlinux-ibmno fix listedUBUNTU-CVE-2026-98012
Ubuntu:26.04:LTSlinux-ibm7.0.0-1017.17UBUNTU-CVE-2026-98012
Ubuntu:22.04:LTSlinux-ibm-6.8no fix listedUBUNTU-CVE-2026-98012
Ubuntu:22.04:LTSlinux-intel-iot-realtimeno fix listedUBUNTU-CVE-2026-98012
Ubuntu:22.04:LTSlinux-intel-iotg5.15.0-1114.120UBUNTU-CVE-2026-98012
Ubuntu:22.04:LTSlinux-kvm5.15.0-1111.116UBUNTU-CVE-2026-98012
Ubuntu:22.04:LTSlinux-lowlatency5.15.0-197.207UBUNTU-CVE-2026-98012
Ubuntu:24.04:LTSlinux-lowlatencyno fix listedUBUNTU-CVE-2026-98012
Ubuntu:22.04:LTSlinux-lowlatency-hwe-5.19no fix listedUBUNTU-CVE-2026-98012
Ubuntu:24.04:LTSlinux-lowlatency-hwe-6.11no fix listedUBUNTU-CVE-2026-98012
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.2no fix listedUBUNTU-CVE-2026-98012
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.5no fix listedUBUNTU-CVE-2026-98012
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.8no fix listedUBUNTU-CVE-2026-98012
Ubuntu:22.04:LTSlinux-nvidia5.15.0-1114.115UBUNTU-CVE-2026-98012
Ubuntu:24.04:LTSlinux-nvidiano fix listedUBUNTU-CVE-2026-98012
Ubuntu:26.04:LTSlinux-nvidiano fix listedUBUNTU-CVE-2026-98012
Ubuntu:24.04:LTSlinux-nvidia-6.11no fix listedUBUNTU-CVE-2026-98012
Ubuntu:24.04:LTSlinux-nvidia-6.17no fix listedUBUNTU-CVE-2026-98012
Ubuntu:22.04:LTSlinux-nvidia-6.2no fix listedUBUNTU-CVE-2026-98012
Ubuntu:22.04:LTSlinux-nvidia-6.5no fix listedUBUNTU-CVE-2026-98012
Ubuntu:22.04:LTSlinux-nvidia-6.8no fix listedUBUNTU-CVE-2026-98012
Ubuntu:24.04:LTSlinux-nvidia-7.0no fix listedUBUNTU-CVE-2026-98012
Ubuntu:26.04:LTSlinux-nvidia-bosno fix listedUBUNTU-CVE-2026-98012
Ubuntu:24.04:LTSlinux-nvidia-lowlatencyno fix listedUBUNTU-CVE-2026-98012
Ubuntu:22.04:LTSlinux-nvidia-tegra5.15.0-1070.72UBUNTU-CVE-2026-98012
Ubuntu:24.04:LTSlinux-nvidia-tegrano fix listedUBUNTU-CVE-2026-98012
Ubuntu:22.04:LTSlinux-nvidia-tegra-igx5.15.0-1059.59UBUNTU-CVE-2026-98012
Ubuntu:22.04:LTSlinux-oem-5.17no fix listedUBUNTU-CVE-2026-98012
Ubuntu:22.04:LTSlinux-oem-6.0no fix listedUBUNTU-CVE-2026-98012
Ubuntu:22.04:LTSlinux-oem-6.1no fix listedUBUNTU-CVE-2026-98012
Ubuntu:24.04:LTSlinux-oem-6.11no fix listedUBUNTU-CVE-2026-98012
Ubuntu:24.04:LTSlinux-oem-6.14no fix listedUBUNTU-CVE-2026-98012
Ubuntu:24.04:LTSlinux-oem-6.17no fix listedUBUNTU-CVE-2026-98012
Ubuntu:22.04:LTSlinux-oem-6.5no fix listedUBUNTU-CVE-2026-98012
Ubuntu:24.04:LTSlinux-oem-6.8no fix listedUBUNTU-CVE-2026-98012
Ubuntu:26.04:LTSlinux-oem-7.07.0.0-1017.17UBUNTU-CVE-2026-98012
Ubuntu:22.04:LTSlinux-oracle5.15.0-1116.122UBUNTU-CVE-2026-98012
Ubuntu:24.04:LTSlinux-oracleno fix listedUBUNTU-CVE-2026-98012
Ubuntu:26.04:LTSlinux-oracle7.0.0-1015.16UBUNTU-CVE-2026-98012
Ubuntu:24.04:LTSlinux-oracle-6.14no fix listedUBUNTU-CVE-2026-98012
Ubuntu:24.04:LTSlinux-oracle-6.17no fix listedUBUNTU-CVE-2026-98012
Ubuntu:22.04:LTSlinux-oracle-6.5no fix listedUBUNTU-CVE-2026-98012
Ubuntu:22.04:LTSlinux-oracle-6.8no fix listedUBUNTU-CVE-2026-98012
Ubuntu:24.04:LTSlinux-oracle-7.0no fix listedUBUNTU-CVE-2026-98012
Ubuntu:22.04:LTSlinux-raspino fix listedUBUNTU-CVE-2026-98012
Ubuntu:24.04:LTSlinux-raspino fix listedUBUNTU-CVE-2026-98012
Ubuntu:26.04:LTSlinux-raspino fix listedUBUNTU-CVE-2026-98012
Ubuntu:24.04:LTSlinux-raspi-realtimeno fix listedUBUNTU-CVE-2026-98012
Ubuntu:22.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-98012
Ubuntu:24.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-98012
Ubuntu:26.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-98012
Ubuntu:22.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2026-98012
Ubuntu:24.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2026-98012
Ubuntu:26.04:LTSlinux-riscv7.0.0-42.42.1UBUNTU-CVE-2026-98012
Ubuntu:22.04:LTSlinux-riscv-5.19no fix listedUBUNTU-CVE-2026-98012
Ubuntu:24.04:LTSlinux-riscv-6.14no fix listedUBUNTU-CVE-2026-98012
Ubuntu:24.04:LTSlinux-riscv-6.17no fix listedUBUNTU-CVE-2026-98012
Ubuntu:22.04:LTSlinux-riscv-6.5no fix listedUBUNTU-CVE-2026-98012
Ubuntu:22.04:LTSlinux-riscv-6.8no fix listedUBUNTU-CVE-2026-98012
Ubuntu:24.04:LTSlinux-riscv-7.07.0.0-42.42.1~24.04.1UBUNTU-CVE-2026-98012
Ubuntu:22.04:LTSlinux-starfive-5.19no fix listedUBUNTU-CVE-2026-98012
Ubuntu:22.04:LTSlinux-starfive-6.2no fix listedUBUNTU-CVE-2026-98012
Ubuntu:22.04:LTSlinux-starfive-6.5no fix listedUBUNTU-CVE-2026-98012
Ubuntu:24.04:LTSlinux-vmwareno fix listedUBUNTU-CVE-2026-98012
Ubuntu:24.04:LTSlinux-xilinxno fix listedUBUNTU-CVE-2026-98012
Ubuntu:22.04:LTSlinux-xilinx-zynqmpno fix listedUBUNTU-CVE-2026-98012

Affected products (as reported)

VendorProductVersions
Linux Linux 4919649699c5f4dbae08b8e2ed536fc9d6c3c2aa – before 4117c528b2de5fdc3e4a7e3626815b616a635cdc548cf048b426729a7a1fa6acd1271c010c9a7380 – before f82fa6f10d4a69322cad0f7a4aa523ce6292a5a0c49ac48fac51a6a54efd5963954d02bacf075085 – before 0692ce5a528df450d64e9f819054177e9d91076f58ae7465f0e7113d45aa88a66bf2d203c71c195e – before e4192bcf83aaab02129644ddf4656fd86e93751f82bd38bd5467ece1ee274b493f51326cf5220a5a – before f3820dce042a673fcb28cc31c87ee14257e21a17e4650d7ae4252f67e997a632adfae0dd74d3a99a – before 534cd7ecbbc6e8a974f4003a5c1557439c6e0a72e4650d7ae4252f67e997a632adfae0dd74d3a99a – before e6c1cb728e389354203a72bc77464c222a247aebe4650d7ae4252f67e997a632adfae0dd74d3a99a – before fb9f88a33c516ea5c0bcd9a22ca288b246b34567
Linux Linux 6.13

References