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Vulnerability · Published Sep 11, 2025 · Assigned by Linux

CVE-2025-39764netfilter: ctnetlink: remove refcounting in expectation dumpers

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

Severity (CVSS NVD)5.5Medium
Exploit odds (30 days)0.2%top 93.2% 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: netfilter: ctnetlink: remove refcounting in expectation dumpers Same pattern as previous patch: do not keep the expectation object alive via refcount, only store a cookie value and then use that as the skip hint for dump resumption. AFAICS this has the same issue as the one resolved in the conntrack dumper, when we do if (!refcount_inc_not_zero(&exp->use)) to increment the refcount, there is a chance that exp == last, which causes a double-increment of the refcount and subsequent memory leak.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12linux6.1.170-1DEBIAN-CVE-2025-39764
Debian:13linux6.12.85-1DEBIAN-CVE-2025-39764
Debian:14linux6.16.3-1DEBIAN-CVE-2025-39764
Ubuntu:22.04:LTSlinux5.15.0-186.196UBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux5.15.0-186.196USN-8575-1
Ubuntu:24.04:LTSlinux6.8.0-136.136USN-8567-1
Ubuntu:24.04:LTSlinux6.8.0-136.136UBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux-allwinner-5.19no fix listedUBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux-aws5.15.0-1112.119USN-8575-2
Ubuntu:22.04:LTSlinux-aws5.15.0-1112.119UBUNTU-CVE-2025-39764
Ubuntu:24.04:LTSlinux-aws6.8.0-1061.64UBUNTU-CVE-2025-39764
Ubuntu:24.04:LTSlinux-aws6.8.0-1061.64USN-8595-2
Ubuntu:22.04:LTSlinux-aws-5.19no fix listedUBUNTU-CVE-2025-39764
Ubuntu:24.04:LTSlinux-aws-6.14no fix listedUBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux-aws-6.2no fix listedUBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux-aws-6.5no fix listedUBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux-aws-6.86.8.0-1061.64~22.04.1UBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux-aws-6.86.8.0-1061.64~22.04.1USN-8595-3
Ubuntu:22.04:LTSlinux-azure5.15.0-1117.126UBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux-azure5.15.0-1117.126USN-8575-3
Ubuntu:24.04:LTSlinux-azure6.8.0-1063.71UBUNTU-CVE-2025-39764
Ubuntu:24.04:LTSlinux-azure6.8.0-1063.71USN-8606-1
Ubuntu:22.04:LTSlinux-azure-5.19no fix listedUBUNTU-CVE-2025-39764
Ubuntu:24.04:LTSlinux-azure-6.11no fix listedUBUNTU-CVE-2025-39764
Ubuntu:24.04:LTSlinux-azure-6.14no fix listedUBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux-azure-6.2no fix listedUBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux-azure-6.5no fix listedUBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux-azure-6.86.8.0-1063.71~22.04.1UBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux-azure-6.86.8.0-1063.71~22.04.1USN-8606-1
Ubuntu:22.04:LTSlinux-azure-fde5.15.0-1117.126USN-8610-1
Ubuntu:22.04:LTSlinux-azure-fde5.15.0-1117.126UBUNTU-CVE-2025-39764
Ubuntu:24.04:LTSlinux-azure-fde6.8.0-1062.69UBUNTU-CVE-2025-39764
Ubuntu:24.04:LTSlinux-azure-fde6.8.0-1062.69USN-8607-1
Ubuntu:25.10linux-azure-fdeno fix listedUBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux-azure-fde-5.19no fix listedUBUNTU-CVE-2025-39764
Ubuntu:24.04:LTSlinux-azure-fde-6.14no fix listedUBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux-azure-fde-6.2no fix listedUBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux-azure-fde-6.86.8.0-1062.69~22.04.1USN-8609-1
Ubuntu:22.04:LTSlinux-azure-fde-6.86.8.0-1062.69~22.04.1UBUNTU-CVE-2025-39764
Ubuntu:24.04:LTSlinux-azure-nvidiano fix listedUBUNTU-CVE-2025-39764
Ubuntu:24.04:LTSlinux-azure-nvidia-6.14no fix listedUBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux-gcp5.15.0-1112.122UBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux-gcp5.15.0-1112.122USN-8575-1
Ubuntu:24.04:LTSlinux-gcp6.8.0-1064.72UBUNTU-CVE-2025-39764
Ubuntu:24.04:LTSlinux-gcp6.8.0-1064.72USN-8567-1
Ubuntu:22.04:LTSlinux-gcp-5.19no fix listedUBUNTU-CVE-2025-39764
Ubuntu:24.04:LTSlinux-gcp-6.11no fix listedUBUNTU-CVE-2025-39764
Ubuntu:24.04:LTSlinux-gcp-6.14no fix listedUBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux-gcp-6.2no fix listedUBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux-gcp-6.5no fix listedUBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux-gcp-6.86.8.0-1064.72~22.04.1USN-8567-1
Ubuntu:22.04:LTSlinux-gcp-6.86.8.0-1064.72~22.04.1UBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux-gke5.15.0-1108.114UBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux-gke5.15.0-1108.114USN-8575-1
Ubuntu:24.04:LTSlinux-gke6.8.0-1059.67USN-8567-1
Ubuntu:24.04:LTSlinux-gke6.8.0-1059.67UBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux-gkeop5.15.0-1095.103USN-8575-1
Ubuntu:22.04:LTSlinux-gkeop5.15.0-1095.103UBUNTU-CVE-2025-39764
Ubuntu:24.04:LTSlinux-gkeop6.8.0-1046.50UBUNTU-CVE-2025-39764
Ubuntu:24.04:LTSlinux-gkeop6.8.0-1046.50USN-8567-1
Ubuntu:22.04:LTSlinux-hwe-5.19no fix listedUBUNTU-CVE-2025-39764
Ubuntu:24.04:LTSlinux-hwe-6.11no fix listedUBUNTU-CVE-2025-39764
Ubuntu:24.04:LTSlinux-hwe-6.14no fix listedUBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux-hwe-6.2no fix listedUBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux-hwe-6.5no fix listedUBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux-hwe-6.86.8.0-136.136~22.04.1USN-8619-1
Ubuntu:22.04:LTSlinux-hwe-6.86.8.0-136.136~22.04.1UBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux-ibm5.15.0-1106.110UBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux-ibm5.15.0-1106.110USN-8575-2
Ubuntu:24.04:LTSlinux-ibm6.8.0-1061.62UBUNTU-CVE-2025-39764
Ubuntu:24.04:LTSlinux-ibm6.8.0-1061.62USN-8574-3
Ubuntu:22.04:LTSlinux-ibm-6.86.8.0-1061.62~22.04.1USN-8574-3
Ubuntu:22.04:LTSlinux-ibm-6.86.8.0-1061.62~22.04.1UBUNTU-CVE-2025-39764
Ubuntu:24.04:LTSlinux-intelno fix listedUBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux-intel-iot-realtimeno fix listedUBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux-intel-iotg5.15.0-1107.113UBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux-intel-iotg5.15.0-1107.113USN-8620-4
Ubuntu:22.04:LTSlinux-kvm5.15.0-1104.109UBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux-kvm5.15.0-1104.109USN-8575-1
Ubuntu:22.04:LTSlinux-lowlatency5.15.0-184.194USN-8575-1
Ubuntu:22.04:LTSlinux-lowlatency5.15.0-184.194UBUNTU-CVE-2025-39764
Ubuntu:24.04:LTSlinux-lowlatency6.8.0-136.136.2UBUNTU-CVE-2025-39764
Ubuntu:24.04:LTSlinux-lowlatency6.8.0-136.136.2USN-8574-2
Ubuntu:22.04:LTSlinux-lowlatency-hwe-5.19no fix listedUBUNTU-CVE-2025-39764
Ubuntu:24.04:LTSlinux-lowlatency-hwe-6.11no fix listedUBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.2no fix listedUBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.5no fix listedUBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.86.8.0-136.136.2~22.04.1USN-8574-2
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.86.8.0-136.136.2~22.04.1UBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux-nvidia5.15.0-1107.108USN-8575-2
Ubuntu:22.04:LTSlinux-nvidia5.15.0-1107.108UBUNTU-CVE-2025-39764
Ubuntu:24.04:LTSlinux-nvidia6.8.0-1059.62UBUNTU-CVE-2025-39764
Ubuntu:24.04:LTSlinux-nvidia6.8.0-1059.62USN-8596-1
Ubuntu:24.04:LTSlinux-nvidia-6.11no fix listedUBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux-nvidia-6.2no fix listedUBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux-nvidia-6.5no fix listedUBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux-nvidia-6.86.8.0-1059.62~22.04.1UBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux-nvidia-6.86.8.0-1059.62~22.04.1USN-8596-1
Ubuntu:24.04:LTSlinux-nvidia-lowlatency6.8.0-1059.62.1USN-8596-1
Ubuntu:24.04:LTSlinux-nvidia-lowlatency6.8.0-1059.62.1UBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux-nvidia-tegra5.15.0-1064.66USN-8576-2
Ubuntu:22.04:LTSlinux-nvidia-tegra5.15.0-1064.66UBUNTU-CVE-2025-39764
Ubuntu:24.04:LTSlinux-nvidia-tegra6.8.0-1030.31UBUNTU-CVE-2025-39764
Ubuntu:24.04:LTSlinux-nvidia-tegra6.8.0-1030.31USN-8574-3
Ubuntu:22.04:LTSlinux-nvidia-tegra-igx5.15.0-1053.53USN-8576-2
Ubuntu:22.04:LTSlinux-nvidia-tegra-igx5.15.0-1053.53UBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux-oem-5.17no fix listedUBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux-oem-6.0no fix listedUBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux-oem-6.1no fix listedUBUNTU-CVE-2025-39764
Ubuntu:24.04:LTSlinux-oem-6.11no fix listedUBUNTU-CVE-2025-39764
Ubuntu:24.04:LTSlinux-oem-6.14no fix listedUBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux-oem-6.5no fix listedUBUNTU-CVE-2025-39764
Ubuntu:24.04:LTSlinux-oem-6.8no fix listedUBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux-oracle5.15.0-1109.115UBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux-oracle5.15.0-1109.115USN-8575-3
Ubuntu:24.04:LTSlinux-oracle6.8.0-1058.61UBUNTU-CVE-2025-39764
Ubuntu:24.04:LTSlinux-oracle6.8.0-1058.61USN-8574-2
Ubuntu:24.04:LTSlinux-oracle-6.14no fix listedUBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux-oracle-6.5no fix listedUBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux-oracle-6.86.8.0-1058.61~22.04.1UBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux-oracle-6.86.8.0-1058.61~22.04.1USN-8595-1
Ubuntu:22.04:LTSlinux-raspi5.15.0-1106.109USN-8668-2
Ubuntu:22.04:LTSlinux-raspi5.15.0-1106.109UBUNTU-CVE-2025-39764
Ubuntu:24.04:LTSlinux-raspi6.8.0-1061.65USN-8665-1
Ubuntu:24.04:LTSlinux-raspi6.8.0-1061.65UBUNTU-CVE-2025-39764
Ubuntu:24.04:LTSlinux-raspi-realtimeno fix listedUBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2025-39764
Ubuntu:24.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2025-39764
Ubuntu:24.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux-riscv-5.19no fix listedUBUNTU-CVE-2025-39764
Ubuntu:24.04:LTSlinux-riscv-6.14no fix listedUBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux-riscv-6.5no fix listedUBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux-riscv-6.86.8.0-136.136~22.04.3UBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux-starfive-5.19no fix listedUBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux-starfive-6.2no fix listedUBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux-starfive-6.5no fix listedUBUNTU-CVE-2025-39764
Ubuntu:24.04:LTSlinux-vmware6.8.0-1008.8UBUNTU-CVE-2025-39764
Ubuntu:24.04:LTSlinux-xilinx6.8.0-1033.34USN-8574-3
Ubuntu:24.04:LTSlinux-xilinx6.8.0-1033.34UBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux-xilinx-zynqmp5.15.0-1075.79UBUNTU-CVE-2025-39764
Ubuntu:22.04:LTSlinux-xilinx-zynqmp5.15.0-1075.79USN-8575-1

Affected products (as reported)

VendorProductVersions
Linux Linux cf6994c2b9812a9f02b99e89df411ffc5db9c779 – before b05500444b8eb97644efdd180839a04a706be97ccf6994c2b9812a9f02b99e89df411ffc5db9c779 – before bada48ad5b0590e318d0f79636ff62a2ef9f4955cf6994c2b9812a9f02b99e89df411ffc5db9c779 – before 64b7684042246e3238464c66894e30ba30c7e851cf6994c2b9812a9f02b99e89df411ffc5db9c779 – before 9e5021a906532ca16e2aac69c0607711e1c70b1fcf6994c2b9812a9f02b99e89df411ffc5db9c779 – before 078d33c95bf534d37aa04269d1ae6158e20082d5cf6994c2b9812a9f02b99e89df411ffc5db9c779 – before a4d634ded4d3d400f115d84f654f316f249531c9cf6994c2b9812a9f02b99e89df411ffc5db9c779 – before 1492e3dcb2be3aa46d1963da96aa9593e4e4db5a
Linux Linux 2.6.23

References