CVE-2026-63963 usb: typec: tcpm: validate VDO count in Discover Identity ACK handlers
A malicious USB device can trigger an out-of-bounds read in the Linux kernel TCPM driver, potentially leaking sensitive memory data to the attacker.
- 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-2026-63963?
CVE-2026-63963 is a 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:
usb: typec: tcpm: validate VDO count in Discover Identity ACK handlers
Properly validate the count passed from a device when calling svdm_consume_identity() or svdm_consume_identity_sop_prime() as the device-controlled value could index off of the static arrays, which could leak data.
Which versions are affected by CVE-2026-63963?
How do I fix CVE-2026-63963?
Apply the vendor's patch.
Is CVE-2026-63963 being exploited?
There is no known exploitation of CVE-2026-63963 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-63963, DEBIAN-CVE-2026-63963, GHSA-p527-vfp9-6cmq, ROOT-OS-DEBIAN-11-CVE-2026-63963, ROOT-OS-DEBIAN-12-CVE-2026-63963, ROOT-OS-UBUNTU-2204-CVE-2026-63963 and 1 more.