CVE-2025-21991 — Improper Validation of Array Index in Linux
Severity
7.8HIGHNVD
OSV8.8OSV5.9OSV5.5OSV4.7OSV4.4
EPSS
0.1%
top 79.39%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
Timeline
PublishedApr 2
Latest updateOct 15
Description
In the Linux kernel, the following vulnerability has been resolved:
x86/microcode/AMD: Fix out-of-bounds on systems with CPU-less NUMA nodes
Currently, load_microcode_amd() iterates over all NUMA nodes, retrieves their
CPU masks and unconditionally accesses per-CPU data for the first CPU of each
mask.
According to Documentation/admin-guide/mm/numaperf.rst:
"Some memory may share the same node as a CPU, and others are provided as
memory only nodes."
Therefore, some node CPU masks may be empt…
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitability: 1.8 | Impact: 5.9