CVE-2026-98199 hwmon: (pmbus/core) increase number of phases and add new mask
A buffer overflow in the Linux kernel PMBus driver allows local attackers to execute arbitrary code or escalate privileges via out-of-bounds writes.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-98199?
CVE-2026-98199 is a memory corruption vulnerability in Linux, published on 6 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
hwmon: (pmbus/core) increase number of phases and add new mask
Increase the number of phases to 16 as a new upcoming device supports such a number.
While at it, add a new mask for controlling the source of the output voltage.
Note (groeck):
This patch was meant to prepare for support of MAX20826 and compatible devices, which support more than 10 phases per page. However, Sashiko reports that the mp2975 driver already supports up to 14 phases, and the mp2856 driver supports up to 12 phases. This already has the potential for out-of-bounds writes when probing the affected chips, making this patch a bug fix.
Which versions are affected by CVE-2026-98199?
How do I fix CVE-2026-98199?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-98199 being exploited?
There is no known exploitation of CVE-2026-98199 in the wild and no public exploit code.
Sources
Also known as AZL-106284, BELL-CVE-2026-98199, DEBIAN-CVE-2026-98199, GHSA-9pcx-3cww-2wxv, UBUNTU-CVE-2026-98199.