CVE-2026-63932 iio: chemical: mhz19b: reject oversized serial replies
A buffer overflow in the Linux kernel MHZ19B sensor driver allows attackers to cause denial of service or execute code via oversized serial replies.
- 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-2026-63932?
CVE-2026-63932 is a memory corruption 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: chemical: mhz19b: reject oversized serial replies
mhz19b_receive_buf() appends each serdev chunk into the fixed MHZ19B_CMD_SIZE receive buffer and advances buf_idx by len without checking that the chunk fits in the remaining space. A large callback can therefore overflow st->buf before the command path validates the reply.
Reset the reply state before each command and reject oversized serial replies before copying them into the fixed buffer. When an oversized reply is detected, wake the waiter and report -EMSGSIZE instead of overwriting st->buf.
Which versions are affected by CVE-2026-63932?
How do I fix CVE-2026-63932?
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-2026-63932 being exploited?
There is no known exploitation of CVE-2026-63932 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-63932, DEBIAN-CVE-2026-63932, GHSA-vrpq-2gcp-g727, UBUNTU-CVE-2026-63932.