A memory leak occurs in the Linux kernel’s ksmbd component when setting a security descriptor attribute. The nk_encode_v4_ntacl() routine allocates a buffer and if a subsequent ndr_write_*() error occurs, that buffer is not released, causing the leak. Repeated failures can deplete kernel memory, potentially bringing the system down or breaking services.

The flaw exists in the Linux kernel’s default ksmbd implementation, affecting all Linux distributions that ship the unrepaired kernel. No version information is supplied, so any system running a kernel before the fix could be vulnerable.

The CVSS score of 7.0 classifies the vulnerability as medium severity, while the EPSS score of < 1% indicates a very low but non‑zero exploitation probability. The flaw is not listed in the CISA KEV catalog, meaning no widespread exploitation has been reported. Attackers would need to drive the ksmbd service with SMB traffic that triggers the security‑descriptor attribute handling; this is inferred from the fact that ksmbd processes SMB requests.