The vulnerability resides in the AppArmor subsystem of the Linux kernel, where the function verify_header mistakenly assigns *ns to NULL on each call. This causes any namespace string allocated by previous iterations to be leaked, resulting in a cumulative memory leak that can eventually exhaust system memory. Additionally, the always‑NULL value breaks namespace consistency checks, potentially leading to further instability within the security framework.

The flaw is present in all Linux kernel releases that include AppArmor before the commit that removes the incorrect assignment. Distributions shipping these kernel versions are therefore impacted; no specific version range is given, so all affected kernels prior to the patch should be considered vulnerable.

EPSS indicates a probability of exploitation below 1% and the vulnerability is not listed in CISA’s KEV catalog, suggesting a low likelihood of real‑world exploitation. Based on the description, it is inferred that an attacker requires local privileges and the ability to trigger repeated AppArmor profile unpacking to exploit the memory leak. The CVSS score is not provided in the input, but the impact is confined to denial of service through memory exhaustion rather than confidentiality or integrity compromise.