The Linux kernel’s psample subsystem contains a flaw where the nla_put() call used to construct netlink attributes fails to clear padding bytes that are added to meet 4‑byte alignment. When data_len is not a multiple of four, the remaining pad bytes remain uninitialized and can be read by the kernel when the attribute is copied to user space. This defect allows an attacker to read adjacent kernel memory, resulting in an information disclosure that could reveal sensitive data, such as cryptographic keys or configuration secrets. The weakness is consistent with CWE‑200: Information Exposure.

The vulnerability impacts all Linux kernel releases that include the psample module and do not contain the patch present in the referenced kernel commits (for example, the commits referenced at git.kernel.org in the advisory). Because psample is part of the standard kernel tree, any distribution that ships the affected kernel version is potentially vulnerable. No specific version numbers are provided, so all kernels prior to the patch should be considered at risk.

The CVSS score of 5.5 and EPSS score of less than 1% indicate a medium severity with a very low exploitation probability; the vulnerability is not listed on the CISA KEV catalog. The attack vector is a local or possibly remote netlink interaction that can be crafted by an attacker with sufficient privileges to send custom netlink messages; it requires manual construction of a packet that targets the psample attribute, which is not trivial but would be straightforward for an attacker with kernel debugging skills. Because the vulnerability leaks kernel data without authenticating the source, an exploited kernel could expose sensitive information. The overall risk can be considered moderate to high, warranting prompt mitigation.