In Linux kernels that did not yet incorporate the fix, an error in the freeing of vmemmap pages caused only the first page of each PMD‑sized block to be released. The remaining pages remained allocated, leaking kernel memory. The flaw stems from misusing pagetable_free() for pages that are neither page tables nor compound objects, which leads to incomplete cleanup. While the vulnerability does not provide a direct code‑execution vector, the persistent leak can degrade system stability and incrementally expose kernel memory contents, potentially aiding information‑disclosure or side‑channel attacks.

All Linux kernel releases prior to the inclusion of commit bf9e4e30f353 ("x86/mm: use pagetable_free()") that contain the buggy vmemmap freeing logic. Exact patched versions are vendor‑specific, but any kernel lacking the commit is vulnerable.

The EPSS score is reported as less than 1% and the vulnerability is not listed in CISA’s KEV catalog, indicating a low probability of active exploitation. Without a CVSS score the severity cannot be quantified precisely, but the primary risk is a kernel‑memory leak that could compromise system reliability and potentially aid reverse‑engineering or information‑disclosure attacks. Attackers would need local or kernel‑level access to trigger the flawed free path, so the likely attack vector is local privilege escalation or exploitation of an ongoing vulnerability that causes a path through this code.