The Linux kernel’s mwifiex Wi‑Fi driver contains a flaw in the MSI‑X interrupt request handling routine. When registration of a PCIe MSI‑X vector fails, the cleanup loop frees the interrupt vector but supplies the wrong device identifier to free_irq. This mismatch prevents the driver from releasing the already‑registered interrupt descriptor, causing an IRQ leak. The unfreed descriptors accumulate over time, potentially exhausting the kernel’s limited MSI‑X resources and leading to system instability or denial of service. This weakness is a resource‑leak problem identified as CWE‑772.

The flaw affects the mwifiex driver that is part of the Linux kernel. Any host running a Linux kernel version that contains the buggy mwifiex implementation before the referenced patch commits (e.g., old stable releases) is vulnerable. Systems that have Wi‑Fi adapters backed by the mwifex driver and that enable MSI‑X interrupt mode are the most directly impacted.

The CVSS score of 7.0 indicates high severity, but the EPSS score is less than 1% and the vulnerability is not listed in CISA’s KEV catalog, suggesting low current exploitation prevalence. While the exact attack vector is not detailed in the CVE description, it is inferred that successful exploitation would require triggering the IRQ failure path, which typically needs privileged manipulation of PCIe configuration or a faulty device firmware. Because the exploit path is indirect and hinges on malformed or uninitialized IRQ requests moderate for environments where MSI‑X is routinely used for mwifex devices, attackers would need significant kernel privileges to provoke the leak.