CVE-2026-63936 iio: adc: mt6359: fix unchecked return value in mt6358_read_imp
An attacker with local access can read uninitialized stack memory via the mt6359 ADC driver, potentially leaking sensitive kernel data.
- 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-2026-63936?
CVE-2026-63936 is a vulnerability in Linux, published on 19 Jul 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:
iio: adc: mt6359: fix unchecked return value in mt6358_read_imp
In mt6358_read_imp(), the variable val_v is passed to regmap_read() but the return value is not checked. If the read fails, val_v remains uninitialized and its random stack content is subsequently reported as a measurement result.
Initialize val_v to zero to ensure a predictable value is reported in case of bus failure and to prevent potential stack data leakage. This also satisfies static analyzers that might otherwise flag the variable as used uninitialized.
Which versions are affected by CVE-2026-63936?
How do I fix CVE-2026-63936?
Apply the vendor's patch.
Is CVE-2026-63936 being exploited?
There is no known exploitation of CVE-2026-63936 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-63936, DEBIAN-CVE-2026-63936, GHSA-856p-gwqh-fxcq, UBUNTU-CVE-2026-63936.