CVE-2025-21994: Linux Kernel

Medium severity, CVSS 5.5. EPSS: 0.3% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix incorrect validation for num_aces field of smb_acl parse_dcal() validate num_aces to allocate posix_ace_state_array. if (num_aces > ULONG_MAX / sizeof(struct smb_ace *)) It is an incorrect validation that we can create an array of size ULONG_MAX. smb_acl has ->size field to calculate actual number of aces in request buffer size. Use this to check invalid num_aces.

Affected products

• Linux Linux Kernel: from 5.15, before 5.15.180 (fixed in 5.15.180); from 5.16, before 6.1.132 (fixed in 6.1.132); from 6.2, before 6.6.85 (fixed in 6.6.85); from 6.7, before 6.12.21 (fixed in 6.12.21); from 6.13, before 6.13.9 (fixed in 6.13.9); version 6.14 only

Published 2025-04-02. Last modified 2026-07-30.