In the Linux kernel High‑Speed Replication (HSR) subsystem, the hsr_dev_finalize() routine can fail after a lower‑device receive handler has already been registered. Frames received during the resulting window may add dynamic nodes to the node database, but the error unwind does not free them, causing a memory leak that could grow kernel memory usage and lead to a denial‑of‑service condition. The patch introduced in this update frees both owned dynamic databases during error unwinding, preventing the leak.

All Linux kernels that include the HSR module and have not yet incorporated the fix are affected. Because the vulnerability is tied to the HSR implementation, any system running a kernel with the current HSR code before the patch is susceptible.

The CVSS score of 5.5 indicates moderate impact, and the EPSS score of <1% suggests a very low likelihood of exploitation. It is inferred from the description that the flaw is exploited locally when an attacker has privileged access to load or configure an HSR interface, making remote exploitation unlikely. The vulnerability is not listed in the CISA KEV catalog, implying no publicly known active exploits.