CVE-2023-53488: 
Linux Kernel vulnerability analysis and mitigation

CVE-2023-53488 is a use-after-free vulnerability in the Linux kernel's IB/hfi1 (InfiniBand Host Fabric Interface) driver that can cause a kernel panic during hotplug device removal. The flaw affects Linux kernel versions from 4.3 through 6.5-rc5 across multiple stable branches. It was published on October 1, 2025, with NVD initial analysis completed on January 21, 2026. The vulnerability carries a CVSS v3.1 base score of 5.5 (Medium) (Feedly).

The root cause is a race condition in the IB/hfi1 driver's hotplug removal path: when a HFI1-compatible InfiniBand device is removed, a pending update_counters work item may execute after the associated memory has already been freed, resulting in a use-after-free condition (classified as NVD-CWE-noinfo due to insufficient public detail). The fix cancels the pending work before freeing memory, eliminating the race window. Exploitation requires local access with low privileges and physical or logical ability to trigger hotplug removal of an InfiniBand device while counter update work is pending (Feedly, kernel.org patches).

Successful exploitation results in a kernel panic and system crash, causing a denial of service and complete system unavailability. There is no confidentiality or integrity impact — the vulnerability exclusively affects availability. Systems running HFI1-based InfiniBand hardware (common in HPC environments) are at risk, and a crash could disrupt workloads dependent on high-performance interconnects (Feedly).

There is no public proof-of-concept exploit and no evidence of in-the-wild exploitation as of the time of publication. The EPSS score is approximately 0.024%, reflecting very low probability of exploitation in the near term. The vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog. Exploitation requires local access with low privileges and the ability to trigger hotplug removal of an InfiniBand device, significantly limiting the practical attack surface (Feedly).

Patches are available for all affected stable kernel branches. Administrators should update to the following fixed versions or later: 4.14.323, 4.19.292, 5.4.254, 5.10.191, 5.15.127, 6.1.46, 6.4.11, and 6.5 (stable). Systems using IB/hfi1 InfiniBand hardware should prioritize kernel updates. As an interim measure, restricting physical access to systems where hotplug removal of InfiniBand devices is possible reduces the attack surface (Feedly, kernel.org patches).