A failure in the hsr_dev_finalize() routine of the Linux kernel’s High‑Speed Replication (HSR) subsystem can leave dynamic node entries in the kernel node database unfreed. Frames received during this short window cause the node database to grow unboundedly, consuming kernel memory over time. This uninitialized memory leak can exhaust available kernel memory, leading to a denial‑of‑service condition for system administrators and users.

Linux kernel builds that include the HSR module and that have not yet incorporated the 2026‑100071 fix are affected. Systems running versions prior to the patch and that enable or load the HSR interface are vulnerable.

The CVSS score of 5.5 denotes moderate impact, while the EPSS score of <1% indicates a very low probability of exploitation in the wild. Because the flaw is tied to the HSR configuration path, it is inferred that an attacker would need privileged local access to configure the HSR interface, making remote exploitation unlikely. The vulnerability is not listed in the CISA KEV catalog, suggesting there are no known active exploits.