CVE-2026-64270 Input: mms114 - reject an oversized device packet size
A stack buffer overflow in the mms114 touch driver allows attackers with I2C access to execute arbitrary code or escalate privileges.
- 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-2026-64270?
CVE-2026-64270 is a high-severity memory corruption vulnerability in Linux kernel, published on 25 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:
Input: mms114 - reject an oversized device packet size
mms114_interrupt() reads a packet of touch data from the device into a fixed-size on-stack buffer
struct mms114_touch touch[MMS114_MAX_TOUCH];
which holds MMS114_MAX_TOUCH (10) events of MMS114_EVENT_SIZE (8) bytes, i.e. 80 bytes. The length of the I2C read into it is taken verbatim from the device:
packet_size = mms114_read_reg(data, MMS114_PACKET_SIZE); if (packet_size <= 0) goto out; ... error = __mms114_read_reg(data, MMS114_INFORMATION, packet_size, (u8 *)touch);
packet_size is a single device register byte (0x0F) and the only check is the lower bound packet_size <= 0; it is never bounded against the size of touch[]. A malfunctioning, malicious or counterfeit controller (or an attacker tampering with the I2C bus) can report a packet_size of up to 255, so __mms114_read_reg() writes up to 175 bytes past the end of touch[] on the IRQ-thread stack: a stack out-of-bounds write that can overwrite the stack canary, saved registers and the return address.
A well-formed device never reports more than the buffer holds, so reject an oversized packet and drop the report, consistent with the handler's other error paths, rather than reading past the buffer.
Weakness: CWE-787
Which versions are affected by CVE-2026-64270?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-64270?
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-2026-64270 being exploited?
There is no known exploitation of CVE-2026-64270 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2026-64270, DEBIAN-CVE-2026-64270, GHSA-q4qw-j7hr-9445, ROOT-OS-UBUNTU-2204-CVE-2026-64270, UBUNTU-CVE-2026-64270.