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Vulnerability · Published Oct 7, 2025 · Assigned by Linux

CVE-2023-53619netfilter: conntrack: Avoid nf_ct_helper_hash uses after free

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 13% 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 87.4% 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: conntrack: Avoid nf_ct_helper_hash uses after free If nf_conntrack_init_start() fails (for example due to a register_nf_conntrack_bpf() failure), the nf_conntrack_helper_fini() clean-up path frees the nf_ct_helper_hash map. When built with NF_CONNTRACK=y, further netfilter modules (e.g: netfilter_conntrack_ftp) can still be loaded and call nf_conntrack_helpers_register(), independently of whether nf_conntrack initialized correctly. This accesses the nf_ct_helper_hash dangling pointer and causes a uaf, possibly leading to random memory corruption. This patch guards nf_conntrack_helper_register() from accessing a freed or uninitialized nf_ct_helper_hash pointer and fixes possible uses-after-free when loading a conntrack module.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12linux6.1.52-1DEBIAN-CVE-2023-53619
Debian:13linux6.4.4-1DEBIAN-CVE-2023-53619
Debian:14linux6.4.4-1DEBIAN-CVE-2023-53619
Ubuntu:22.04:LTSlinux5.15.0-86.96UBUNTU-CVE-2023-53619
Ubuntu:22.04:LTSlinux-allwinner-5.19no fix listedUBUNTU-CVE-2023-53619
Ubuntu:22.04:LTSlinux-aws5.15.0-1047.52UBUNTU-CVE-2023-53619
Ubuntu:22.04:LTSlinux-aws-5.19no fix listedUBUNTU-CVE-2023-53619
Ubuntu:22.04:LTSlinux-aws-6.2no fix listedUBUNTU-CVE-2023-53619
Ubuntu:22.04:LTSlinux-aws-6.5no fix listedUBUNTU-CVE-2023-53619
Ubuntu:22.04:LTSlinux-azure5.15.0-1049.56UBUNTU-CVE-2023-53619
Ubuntu:22.04:LTSlinux-azure-5.19no fix listedUBUNTU-CVE-2023-53619
Ubuntu:24.04:LTSlinux-azure-6.11no fix listedUBUNTU-CVE-2023-53619
Ubuntu:22.04:LTSlinux-azure-6.2no fix listedUBUNTU-CVE-2023-53619
Ubuntu:22.04:LTSlinux-azure-6.5no fix listedUBUNTU-CVE-2023-53619
Ubuntu:22.04:LTSlinux-azure-fde5.15.0-1049.56.1UBUNTU-CVE-2023-53619
Ubuntu:22.04:LTSlinux-azure-fde-5.19no fix listedUBUNTU-CVE-2023-53619
Ubuntu:22.04:LTSlinux-azure-fde-6.2no fix listedUBUNTU-CVE-2023-53619
Ubuntu:22.04:LTSlinux-gcp5.15.0-1044.52UBUNTU-CVE-2023-53619
Ubuntu:22.04:LTSlinux-gcp-5.19no fix listedUBUNTU-CVE-2023-53619
Ubuntu:24.04:LTSlinux-gcp-6.11no fix listedUBUNTU-CVE-2023-53619
Ubuntu:22.04:LTSlinux-gcp-6.2no fix listedUBUNTU-CVE-2023-53619
Ubuntu:22.04:LTSlinux-gcp-6.5no fix listedUBUNTU-CVE-2023-53619
Ubuntu:22.04:LTSlinux-gke5.15.0-1044.49UBUNTU-CVE-2023-53619
Ubuntu:22.04:LTSlinux-gkeop5.15.0-1030.35UBUNTU-CVE-2023-53619
Ubuntu:22.04:LTSlinux-hwe-5.19no fix listedUBUNTU-CVE-2023-53619
Ubuntu:24.04:LTSlinux-hwe-6.11no fix listedUBUNTU-CVE-2023-53619
Ubuntu:22.04:LTSlinux-hwe-6.2no fix listedUBUNTU-CVE-2023-53619
Ubuntu:22.04:LTSlinux-hwe-6.5no fix listedUBUNTU-CVE-2023-53619
Ubuntu:22.04:LTSlinux-ibm5.15.0-1040.43UBUNTU-CVE-2023-53619
Ubuntu:24.04:LTSlinux-intelno fix listedUBUNTU-CVE-2023-53619
Ubuntu:22.04:LTSlinux-intel-iot-realtimeno fix listedUBUNTU-CVE-2023-53619
Ubuntu:22.04:LTSlinux-intel-iotg5.15.0-1043.49UBUNTU-CVE-2023-53619
Ubuntu:22.04:LTSlinux-kvm5.15.0-1044.49UBUNTU-CVE-2023-53619
Ubuntu:22.04:LTSlinux-lowlatency5.15.0-86.95UBUNTU-CVE-2023-53619
Ubuntu:22.04:LTSlinux-lowlatency-hwe-5.19no fix listedUBUNTU-CVE-2023-53619
Ubuntu:24.04:LTSlinux-lowlatency-hwe-6.11no fix listedUBUNTU-CVE-2023-53619
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.2no fix listedUBUNTU-CVE-2023-53619
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.5no fix listedUBUNTU-CVE-2023-53619
Ubuntu:22.04:LTSlinux-nvidia5.15.0-1037.37UBUNTU-CVE-2023-53619
Ubuntu:22.04:LTSlinux-nvidia-6.2no fix listedUBUNTU-CVE-2023-53619
Ubuntu:22.04:LTSlinux-nvidia-6.5no fix listedUBUNTU-CVE-2023-53619
Ubuntu:22.04:LTSlinux-nvidia-tegra5.15.0-1018.18UBUNTU-CVE-2023-53619
Ubuntu:22.04:LTSlinux-nvidia-tegra-igx5.15.0-1005.5UBUNTU-CVE-2023-53619
Ubuntu:22.04:LTSlinux-oem-5.17no fix listedUBUNTU-CVE-2023-53619
Ubuntu:22.04:LTSlinux-oem-6.0no fix listedUBUNTU-CVE-2023-53619
Ubuntu:22.04:LTSlinux-oem-6.1no fix listedUBUNTU-CVE-2023-53619
Ubuntu:24.04:LTSlinux-oem-6.11no fix listedUBUNTU-CVE-2023-53619
Ubuntu:22.04:LTSlinux-oem-6.5no fix listedUBUNTU-CVE-2023-53619
Ubuntu:24.04:LTSlinux-oem-6.8no fix listedUBUNTU-CVE-2023-53619
Ubuntu:22.04:LTSlinux-oracle5.15.0-1045.51UBUNTU-CVE-2023-53619
Ubuntu:22.04:LTSlinux-oracle-6.5no fix listedUBUNTU-CVE-2023-53619
Ubuntu:22.04:LTSlinux-raspi5.15.0-1040.43UBUNTU-CVE-2023-53619
Ubuntu:24.04:LTSlinux-raspi-realtimeno fix listedUBUNTU-CVE-2023-53619
Ubuntu:22.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2023-53619
Ubuntu:24.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2023-53619
Ubuntu:22.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2023-53619
Ubuntu:24.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2023-53619
Ubuntu:22.04:LTSlinux-riscv-5.19no fix listedUBUNTU-CVE-2023-53619
Ubuntu:22.04:LTSlinux-riscv-6.5no fix listedUBUNTU-CVE-2023-53619
Ubuntu:22.04:LTSlinux-starfive-5.19no fix listedUBUNTU-CVE-2023-53619
Ubuntu:22.04:LTSlinux-starfive-6.2no fix listedUBUNTU-CVE-2023-53619
Ubuntu:22.04:LTSlinux-starfive-6.5no fix listedUBUNTU-CVE-2023-53619
Ubuntu:22.04:LTSlinux-xilinx-zynqmp5.15.0-1025.29UBUNTU-CVE-2023-53619

Affected products (as reported)

VendorProductVersions
Linux Linux 12f7a505331e6b2754684b509f2ac8f0011ce644 – before 4ee69c91cb8f9ca144bc0861969e5a1a3c6152a712f7a505331e6b2754684b509f2ac8f0011ce644 – before 00716f25f9697d02a0d9bd622575c7c7321ba3d012f7a505331e6b2754684b509f2ac8f0011ce644 – before 61c7a5256543ae7d24cd9d21853d514c8632e1e912f7a505331e6b2754684b509f2ac8f0011ce644 – before 8289d422f5e484efe4a565fe18e862ecd621c17512f7a505331e6b2754684b509f2ac8f0011ce644 – before 6f03ce2f1abcb9f9d0511e3659ca6eb60e39f56612f7a505331e6b2754684b509f2ac8f0011ce644 – before 05561f822f27b9fa88fa5504ddec34bf3883303412f7a505331e6b2754684b509f2ac8f0011ce644 – before fce5cc7cbd4b92f979bf02c9ec5fb69aaeba92d712f7a505331e6b2754684b509f2ac8f0011ce644 – before 6eef7a2b933885a17679eb8ed0796ddf0ee5309b
Linux Linux 3.6

References