CVE-2025-21963: Linux Kernel

Medium severity, CVSS 5.5. EPSS: 0.2% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: cifs: Fix integer overflow while processing acdirmax mount option User-provided mount parameter acdirmax of type u32 is intended to have an upper limit, but before it is validated, the value is converted from seconds to jiffies which can lead to an integer overflow. Found by Linux Verification Center (linuxtesting.org) with SVACE.

Affected products

• Linux Linux Kernel: from 5.12, 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 6.6.84 (fixed in 6.6.84); from 6.7, before 6.12.20 (fixed in 6.12.20); from 6.13, before 6.13.8 (fixed in 6.13.8); version 6.14 only

Published 2025-04-01. Last modified 2026-06-17.