The vulnerability is a use‑after‑free in the Linux kernel HSR (High‑Availability Seamless Redundancy) network module. HSR node‑list and node‑status generic‑netlink operations run under an RCU read lock and walk the node database, but the HSR teardown function removes node entries with a plain list_del and frees them immediately. This allows a netlink reader to keep a pointer to a node structure across the node deletion, resulting in a slab‑use‑after‑free when the reader accesses the node’s data. The flaw is a resource‑management error (CWE‑825) that can corrupt memory and potentially allow an attacker with access to generic‑netlink interfaces to cause a crash or execute arbitrary code.

All Linux kernel installations that include the HSR module before the fix. The vulnerability applies to frames of the Linux kernel where the HSR network driver is built and loaded, regardless of distribution or kernel version, because no specific version list is provided in the CNA data.

The CVSS score of 7.8 marks this issue as High severity, and the EPSS score of (<1%) indicates a very low current likelihood of exploitation. It is not listed in CISA’s KEV catalog. Exploitation would require an attacker to be able to send crafted generic‑netlink messages to the HSR module or to have a process already holding an RCU reader reference to a node. The attack vector is therefore local or privileged rather than remote. While the exploitation window is constrained, the memory corruption can lead to denial of service or privilege escalation.