CVE-2026-63943 Input: xpad - fix out-of-bounds access for Share button
A malicious USB controller can trigger an out-of-bounds read in the xpad driver, potentially causing a kernel crash or leaking memory.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-63943?
CVE-2026-63943 is a memory corruption vulnerability in Linux, published on 19 Jul 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
In the Linux kernel, the following vulnerability has been resolved:
Input: xpad - fix out-of-bounds access for Share button
xpadone_process_packet() receives len directly from urb->actual_length and uses it to index the share-button byte at data[len - 18] or data[len - 26]. Since both len and data[0] are under the device's control, a broken controller can send a GIP_CMD_INPUT packet with actual_length < 18 (e.g. 5 bytes) and reach this code path, causing accesses beyond the actual array.
Fix this by calculating the offset and checking bounds against the packet length.
Which versions are affected by CVE-2026-63943?
How do I fix CVE-2026-63943?
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-2026-63943 being exploited?
There is no known exploitation of CVE-2026-63943 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-63943, DEBIAN-CVE-2026-63943, GHSA-p7rq-pjmq-p6gw, UBUNTU-CVE-2026-63943.