CVE-2025-38257

Medium

Elevated severity or exploit probability.

CVSS base

7.3 HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:H

EPSS — probability of exploitation (30 days)

0.2%

5.3th percentile

CISA KEV

Not listed

Weakness / dates

—

Published 2025-07-09 · modified 2026-07-30

CVSS breakdown

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:H

Attack Vector	L	Local
Attack Complexity	L	Low
Privileges Required	L	Low
User Interaction	N	None
Scope	U	Unchanged
Confidentiality	H	High
Integrity	L	Low
Availability	H	High

Timeline

2025-07-09 — Published (NVD)
2026-07-30 — Last modified (NVD)

Description

In the Linux kernel, the following vulnerability has been resolved: s390/pkey: Prevent overflow in size calculation for memdup_user() Number of apqn target list entries contained in 'nr_apqns' variable is determined by userspace via an ioctl call so the result of the product in calculation of size passed to memdup_user() may overflow. In this case the actual size of the allocated area and the value describing it won't be in sync leading to various types of unpredictable behaviour later. Use a proper memdup_array_user() helper which returns an error if an overflow is detected. Note that it is different from when nr_apqns is initially zero - that case is considered valid and should be handled in subsequent pkey_handler implementations. Found by Linux Verification Center (linuxtesting.org).

Affected

debian linux

References

Official: NVD · CVE.org