CVE-2026-23323 hwmon: (macsmc) Fix regressions in Apple Silicon SMC hwmon driver
Out-of-bounds memory access in the Apple Silicon SMC hwmon driver allows potential code execution or system crash due to incorrect sensor array assignment.
- 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-2026-23323?
CVE-2026-23323 is a high-severity memory corruption vulnerability in Linux kernel, published on 25 Mar 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: (macsmc) Fix regressions in Apple Silicon SMC hwmon driver
The recently added macsmc-hwmon driver contained several critical bugs in its sensor population logic and float conversion routines.
Specifically: - The voltage sensor population loop used the wrong prefix ("volt-" instead of "voltage-") and incorrectly assigned sensors to the temperature sensor array (hwmon->temp.sensors) instead of the voltage sensor array (hwmon->volt.sensors). This would lead to out-of-bounds memory access or data corruption when both temperature and voltage sensors were present. - The float conversion in macsmc_hwmon_write_f32() had flawed exponent logic for values >= 2^24 and lacked masking for the mantissa, which could lead to incorrect values being written to the SMC.
Fix these issues to ensure correct sensor registration and reliable manual fan control.
Confirm that the reported overflow in FIELD_PREP is fixed by declaring macsmc_hwmon_write_f32() as __always_inline for a compile test.
Weakness: CWE-787
Which versions are affected by CVE-2026-23323?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-23323?
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-2026-23323 being exploited?
There is no known exploitation of CVE-2026-23323 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2026-23323, GHSA-xf4v-3mcr-w96x, UBUNTU-CVE-2026-23323.