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Vulnerability · Published Mar 20, 2026 · Assigned by Linux

CVE-2026-23274netfilter: xt_IDLETIMER: reject rev0 reuse of ALARM timer labels

High 7.8

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 0.2% (higher than 8% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.8High
Exploit odds (30 days)0.2%top 92.0% 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: netfilter: xt_IDLETIMER: reject rev0 reuse of ALARM timer labels IDLETIMER revision 0 rules reuse existing timers by label and always call mod_timer() on timer->timer. If the label was created first by revision 1 with XT_IDLETIMER_ALARM, the object uses alarm timer semantics and timer->timer is never initialized. Reusing that object from revision 0 causes mod_timer() on an uninitialized timer_list, triggering debugobjects warnings and possible panic when panic_on_warn=1. Fix this by rejecting revision 0 rule insertion when an existing timer with the same label is of ALARM type.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12linux6.1.170-1DEBIAN-CVE-2026-23274
Debian:13linux6.12.85-1DEBIAN-CVE-2026-23274
Debian:14linux6.19.10-1DEBIAN-CVE-2026-23274
Ubuntu:22.04:LTSlinux5.15.0-179.189USN-8279-1
Ubuntu:22.04:LTSlinux5.15.0-179.189UBUNTU-CVE-2026-23274
Ubuntu:24.04:LTSlinux6.8.0-117.117UBUNTU-CVE-2026-23274
Ubuntu:25.10linux6.17.0-29.29UBUNTU-CVE-2026-23274
Ubuntu:25.10linux6.17.0-29.29USN-8277-1
Ubuntu:22.04:LTSlinux-allwinner-5.19no fix listedUBUNTU-CVE-2026-23274
Ubuntu:22.04:LTSlinux-aws5.15.0-1108.115UBUNTU-CVE-2026-23274
Ubuntu:22.04:LTSlinux-aws5.15.0-1108.115USN-8279-1
Ubuntu:24.04:LTSlinux-aws6.8.0-1055.58UBUNTU-CVE-2026-23274
Ubuntu:25.10linux-aws6.17.0-1015.15USN-8277-1
Ubuntu:25.10linux-aws6.17.0-1015.15UBUNTU-CVE-2026-23274
Ubuntu:22.04:LTSlinux-aws-5.19no fix listedUBUNTU-CVE-2026-23274
Ubuntu:24.04:LTSlinux-aws-6.14no fix listedUBUNTU-CVE-2026-23274
Ubuntu:24.04:LTSlinux-aws-6.176.17.0-1017.17~24.04.1UBUNTU-CVE-2026-23274
Ubuntu:24.04:LTSlinux-aws-6.176.17.0-1017.17~24.04.1USN-8374-1
Ubuntu:22.04:LTSlinux-aws-6.2no fix listedUBUNTU-CVE-2026-23274
Ubuntu:22.04:LTSlinux-aws-6.5no fix listedUBUNTU-CVE-2026-23274
Ubuntu:22.04:LTSlinux-aws-6.86.8.0-1057.60~22.04.1UBUNTU-CVE-2026-23274
Ubuntu:22.04:LTSlinux-azure5.15.0-1114.123USN-8426-2
Ubuntu:22.04:LTSlinux-azure5.15.0-1114.123UBUNTU-CVE-2026-23274
Ubuntu:24.04:LTSlinux-azure6.8.0-1056.62UBUNTU-CVE-2026-23274
Ubuntu:25.10linux-azure6.17.0-1015.15UBUNTU-CVE-2026-23274
Ubuntu:25.10linux-azure6.17.0-1015.15USN-8310-1
Ubuntu:22.04:LTSlinux-azure-5.19no fix listedUBUNTU-CVE-2026-23274
Ubuntu:24.04:LTSlinux-azure-6.11no fix listedUBUNTU-CVE-2026-23274
Ubuntu:24.04:LTSlinux-azure-6.14no fix listedUBUNTU-CVE-2026-23274
Ubuntu:24.04:LTSlinux-azure-6.176.17.0-1015.15~24.04.1USN-8310-1
Ubuntu:24.04:LTSlinux-azure-6.176.17.0-1015.15~24.04.1UBUNTU-CVE-2026-23274
Ubuntu:22.04:LTSlinux-azure-6.2no fix listedUBUNTU-CVE-2026-23274
Ubuntu:22.04:LTSlinux-azure-6.5no fix listedUBUNTU-CVE-2026-23274
Ubuntu:22.04:LTSlinux-azure-6.86.8.0-1059.65~22.04.1UBUNTU-CVE-2026-23274
Ubuntu:22.04:LTSlinux-azure-fde5.15.0-1114.123UBUNTU-CVE-2026-23274
Ubuntu:24.04:LTSlinux-azure-fde6.8.0-1058.65UBUNTU-CVE-2026-23274
Ubuntu:25.10linux-azure-fdeno fix listedUBUNTU-CVE-2026-23274
Ubuntu:22.04:LTSlinux-azure-fde-5.19no fix listedUBUNTU-CVE-2026-23274
Ubuntu:24.04:LTSlinux-azure-fde-6.14no fix listedUBUNTU-CVE-2026-23274
Ubuntu:22.04:LTSlinux-azure-fde-6.2no fix listedUBUNTU-CVE-2026-23274
Ubuntu:22.04:LTSlinux-azure-fde-6.86.8.0-1058.65~22.04.1UBUNTU-CVE-2026-23274
Ubuntu:24.04:LTSlinux-azure-nvidiano fix listedUBUNTU-CVE-2026-23274
Ubuntu:24.04:LTSlinux-azure-nvidia-6.14no fix listedUBUNTU-CVE-2026-23274
Ubuntu:22.04:LTSlinux-gcp5.15.0-1108.117UBUNTU-CVE-2026-23274
Ubuntu:22.04:LTSlinux-gcp5.15.0-1108.117USN-8279-1
Ubuntu:24.04:LTSlinux-gcp6.8.0-1058.61UBUNTU-CVE-2026-23274
Ubuntu:25.10linux-gcp6.17.0-1018.19UBUNTU-CVE-2026-23274
Ubuntu:25.10linux-gcp6.17.0-1018.19USN-8374-1
Ubuntu:22.04:LTSlinux-gcp-5.19no fix listedUBUNTU-CVE-2026-23274
Ubuntu:24.04:LTSlinux-gcp-6.11no fix listedUBUNTU-CVE-2026-23274
Ubuntu:24.04:LTSlinux-gcp-6.14no fix listedUBUNTU-CVE-2026-23274
Ubuntu:24.04:LTSlinux-gcp-6.176.17.0-1018.19~24.04.1UBUNTU-CVE-2026-23274
Ubuntu:24.04:LTSlinux-gcp-6.176.17.0-1018.19~24.04.1USN-8374-1
Ubuntu:22.04:LTSlinux-gcp-6.2no fix listedUBUNTU-CVE-2026-23274
Ubuntu:22.04:LTSlinux-gcp-6.5no fix listedUBUNTU-CVE-2026-23274
Ubuntu:22.04:LTSlinux-gcp-6.86.8.0-1060.63~22.04.1UBUNTU-CVE-2026-23274
Ubuntu:22.04:LTSlinux-gke5.15.0-1104.110UBUNTU-CVE-2026-23274
Ubuntu:22.04:LTSlinux-gke5.15.0-1104.110USN-8279-1
Ubuntu:24.04:LTSlinux-gke6.8.0-1054.60UBUNTU-CVE-2026-23274
Ubuntu:22.04:LTSlinux-gkeop5.15.0-1091.99USN-8279-1
Ubuntu:22.04:LTSlinux-gkeop5.15.0-1091.99UBUNTU-CVE-2026-23274
Ubuntu:24.04:LTSlinux-gkeop6.8.0-1041.44UBUNTU-CVE-2026-23274
Ubuntu:22.04:LTSlinux-hwe-5.19no fix listedUBUNTU-CVE-2026-23274
Ubuntu:24.04:LTSlinux-hwe-6.11no fix listedUBUNTU-CVE-2026-23274
Ubuntu:24.04:LTSlinux-hwe-6.14no fix listedUBUNTU-CVE-2026-23274
Ubuntu:24.04:LTSlinux-hwe-6.176.17.0-29.29~24.04.1USN-8277-1
Ubuntu:24.04:LTSlinux-hwe-6.176.17.0-29.29~24.04.1UBUNTU-CVE-2026-23274
Ubuntu:22.04:LTSlinux-hwe-6.2no fix listedUBUNTU-CVE-2026-23274
Ubuntu:22.04:LTSlinux-hwe-6.5no fix listedUBUNTU-CVE-2026-23274
Ubuntu:22.04:LTSlinux-hwe-6.86.8.0-124.124~22.04.1UBUNTU-CVE-2026-23274
Ubuntu:22.04:LTSlinux-ibm5.15.0-1102.105USN-8279-1
Ubuntu:22.04:LTSlinux-ibm5.15.0-1102.105UBUNTU-CVE-2026-23274
Ubuntu:24.04:LTSlinux-ibm6.8.0-1055.56UBUNTU-CVE-2026-23274
Ubuntu:22.04:LTSlinux-ibm-6.86.8.0-1055.56~22.04.1UBUNTU-CVE-2026-23274
Ubuntu:22.04:LTSlinux-intel-iot-realtimeno fix listedUBUNTU-CVE-2026-23274
Ubuntu:22.04:LTSlinux-intel-iotg5.15.0-1103.109USN-8279-1
Ubuntu:22.04:LTSlinux-intel-iotg5.15.0-1103.109UBUNTU-CVE-2026-23274
Ubuntu:22.04:LTSlinux-kvm5.15.0-1100.105USN-8279-1
Ubuntu:22.04:LTSlinux-kvm5.15.0-1100.105UBUNTU-CVE-2026-23274
Ubuntu:22.04:LTSlinux-lowlatency5.15.0-178.188UBUNTU-CVE-2026-23274
Ubuntu:22.04:LTSlinux-lowlatency5.15.0-178.188USN-8291-3
Ubuntu:24.04:LTSlinux-lowlatency6.8.0-117.117.1UBUNTU-CVE-2026-23274
Ubuntu:22.04:LTSlinux-lowlatency-hwe-5.19no fix listedUBUNTU-CVE-2026-23274
Ubuntu:24.04:LTSlinux-lowlatency-hwe-6.11no fix listedUBUNTU-CVE-2026-23274
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.2no fix listedUBUNTU-CVE-2026-23274
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.5no fix listedUBUNTU-CVE-2026-23274
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.86.8.0-117.117.1~22.04.1UBUNTU-CVE-2026-23274
Ubuntu:22.04:LTSlinux-nvidia5.15.0-1103.104USN-8279-1
Ubuntu:22.04:LTSlinux-nvidia5.15.0-1103.104UBUNTU-CVE-2026-23274
Ubuntu:24.04:LTSlinux-nvidia6.8.0-1054.57UBUNTU-CVE-2026-23274
Ubuntu:24.04:LTSlinux-nvidia-6.11no fix listedUBUNTU-CVE-2026-23274
Ubuntu:24.04:LTSlinux-nvidia-6.176.17.0-1026.26USN-8508-1
Ubuntu:24.04:LTSlinux-nvidia-6.176.17.0-1026.26UBUNTU-CVE-2026-23274
Ubuntu:22.04:LTSlinux-nvidia-6.2no fix listedUBUNTU-CVE-2026-23274
Ubuntu:22.04:LTSlinux-nvidia-6.5no fix listedUBUNTU-CVE-2026-23274
Ubuntu:22.04:LTSlinux-nvidia-6.86.8.0-1054.57~22.04.1UBUNTU-CVE-2026-23274
Ubuntu:24.04:LTSlinux-nvidia-lowlatency6.8.0-1054.57.1UBUNTU-CVE-2026-23274
Ubuntu:22.04:LTSlinux-nvidia-tegra5.15.0-1060.60USN-8279-1
Ubuntu:22.04:LTSlinux-nvidia-tegra5.15.0-1060.60UBUNTU-CVE-2026-23274
Ubuntu:24.04:LTSlinux-nvidia-tegra6.8.0-1024.24UBUNTU-CVE-2026-23274
Ubuntu:22.04:LTSlinux-nvidia-tegra-igx5.15.0-1049.49USN-8279-3
Ubuntu:22.04:LTSlinux-nvidia-tegra-igx5.15.0-1049.49UBUNTU-CVE-2026-23274
Ubuntu:22.04:LTSlinux-oem-5.17no fix listedUBUNTU-CVE-2026-23274
Ubuntu:22.04:LTSlinux-oem-6.0no fix listedUBUNTU-CVE-2026-23274
Ubuntu:22.04:LTSlinux-oem-6.1no fix listedUBUNTU-CVE-2026-23274
Ubuntu:24.04:LTSlinux-oem-6.11no fix listedUBUNTU-CVE-2026-23274
Ubuntu:24.04:LTSlinux-oem-6.14no fix listedUBUNTU-CVE-2026-23274
Ubuntu:24.04:LTSlinux-oem-6.176.17.0-1023.23UBUNTU-CVE-2026-23274
Ubuntu:24.04:LTSlinux-oem-6.176.17.0-1023.23USN-8277-1
Ubuntu:22.04:LTSlinux-oem-6.5no fix listedUBUNTU-CVE-2026-23274
Ubuntu:24.04:LTSlinux-oem-6.8no fix listedUBUNTU-CVE-2026-23274
Ubuntu:22.04:LTSlinux-oracle5.15.0-1105.111USN-8279-1
Ubuntu:22.04:LTSlinux-oracle5.15.0-1105.111UBUNTU-CVE-2026-23274
Ubuntu:24.04:LTSlinux-oracle6.8.0-1054.55UBUNTU-CVE-2026-23274
Ubuntu:25.10linux-oracle6.17.0-1014.14USN-8277-1
Ubuntu:25.10linux-oracle6.17.0-1014.14UBUNTU-CVE-2026-23274
Ubuntu:24.04:LTSlinux-oracle-6.14no fix listedUBUNTU-CVE-2026-23274
Ubuntu:24.04:LTSlinux-oracle-6.176.17.0-1014.14~24.04.1USN-8277-2
Ubuntu:24.04:LTSlinux-oracle-6.176.17.0-1014.14~24.04.1UBUNTU-CVE-2026-23274
Ubuntu:22.04:LTSlinux-oracle-6.5no fix listedUBUNTU-CVE-2026-23274
Ubuntu:22.04:LTSlinux-oracle-6.86.8.0-1054.55~22.04.1UBUNTU-CVE-2026-23274
Ubuntu:22.04:LTSlinux-raspi5.15.0-1102.105UBUNTU-CVE-2026-23274
Ubuntu:22.04:LTSlinux-raspi5.15.0-1102.105USN-8279-1
Ubuntu:24.04:LTSlinux-raspi6.8.0-1056.60UBUNTU-CVE-2026-23274
Ubuntu:25.10linux-raspi6.17.0-1017.17USN-8277-1
Ubuntu:25.10linux-raspi6.17.0-1017.17UBUNTU-CVE-2026-23274
Ubuntu:24.04:LTSlinux-raspi-realtimeno fix listedUBUNTU-CVE-2026-23274
Ubuntu:22.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-23274
Ubuntu:24.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-23274
Ubuntu:25.10linux-realtime6.17.0-1013.15UBUNTU-CVE-2026-23274
Ubuntu:25.10linux-realtime6.17.0-1013.15USN-8277-1
Ubuntu:22.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2026-23274
Ubuntu:24.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2026-23274
Ubuntu:25.10linux-riscv6.17.0-29.29.1UBUNTU-CVE-2026-23274
Ubuntu:22.04:LTSlinux-riscv-5.19no fix listedUBUNTU-CVE-2026-23274
Ubuntu:24.04:LTSlinux-riscv-6.14no fix listedUBUNTU-CVE-2026-23274
Ubuntu:24.04:LTSlinux-riscv-6.176.17.0-29.29.1~24.04.1UBUNTU-CVE-2026-23274
Ubuntu:22.04:LTSlinux-riscv-6.5no fix listedUBUNTU-CVE-2026-23274
Ubuntu:22.04:LTSlinux-riscv-6.86.8.0-117.117~22.04.1UBUNTU-CVE-2026-23274
Ubuntu:22.04:LTSlinux-starfive-5.19no fix listedUBUNTU-CVE-2026-23274
Ubuntu:22.04:LTSlinux-starfive-6.2no fix listedUBUNTU-CVE-2026-23274
Ubuntu:22.04:LTSlinux-starfive-6.5no fix listedUBUNTU-CVE-2026-23274
Ubuntu:24.04:LTSlinux-xilinx6.8.0-1032.33UBUNTU-CVE-2026-23274
Ubuntu:22.04:LTSlinux-xilinx-zynqmp5.15.0-1074.78UBUNTU-CVE-2026-23274
Ubuntu:22.04:LTSlinux-xilinx-zynqmp5.15.0-1074.78USN-8528-1

Affected products (as reported)

VendorProductVersions
Linux Linux 68983a354a655c35d3fb204489d383a2a051fda7 – before 32e937dc6e97f5ed3cdfe3fc0b2b19a05e23fa4468983a354a655c35d3fb204489d383a2a051fda7 – before 144f88054ba0180467356f40895bd660b5dceeec68983a354a655c35d3fb204489d383a2a051fda7 – before 28c7cfaf0c0ab17cbd7754092116fd1af45271f968983a354a655c35d3fb204489d383a2a051fda7 – before 54080355999381fed4a26129579a5765bab8749168983a354a655c35d3fb204489d383a2a051fda7 – before 5e7ece24c5cb75a60402aad4d803c7898ea40aa968983a354a655c35d3fb204489d383a2a051fda7 – before f5ef97c13165542480a6ffdbe6f09f40bbb7cbf168983a354a655c35d3fb204489d383a2a051fda7 – before f228b9ae2a7e84d1153616d8e71c4236cb1f130968983a354a655c35d3fb204489d383a2a051fda7 – before 329f0b9b48ee6ab59d1ab72fef55fe8c6463a6cf
Linux Linux 5.7

Weakness: CWE-758 · Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

References