CVE-2026-72395 hwmon: (pmbus) Fix passing events to regulator core
A logic error in the Linux kernel PMBus driver bypasses critical hardware protection triggers when multiple regulator faults occur simultaneously.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-72395?
CVE-2026-72395 is a high-severity vulnerability in Linux, published on 15 Aug 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) Fix passing events to regulator core
Sashiko reports:
Commit 754bd2b4a084 ("hwmon: (pmbus/core) Protect regulator operations with mutex") introduced a worker to batch regulator events over time using atomic_or(). The delayed worker then passes the combined bitmask unmodified to regulator_notifier_call_chain().
The core regulator subsystem's regulator_handle_critical() function evaluates the event parameter using a strict switch statement. If multiple distinct faults occur before the worker runs (e.g., REGULATOR_EVENT_UNDER_VOLTAGE | REGULATOR_EVENT_OVER_CURRENT), the combined bitmask fails to match any case. This leaves the reason as NULL and completely bypasses the critical hw_protection_trigger().
Fix the problem by passing events bit by bit to the regulator event handler.
Which versions are affected by CVE-2026-72395?
How do I fix CVE-2026-72395?
Apply the vendor's patch.
Is CVE-2026-72395 being exploited?
There is no known exploitation of CVE-2026-72395 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-72395, DEBIAN-CVE-2026-72395, GHSA-w4gm-vhrh-5h95, UBUNTU-CVE-2026-72395.