CVE-2026-63904: usb: usbtmc: check URB actual_length for interrupt-IN notifications

High 7.1 EPSS 0.2% Linux kernel

In the Linux kernel, the following vulnerability has been resolved: usb: usbtmc: check URB actual_length for interrupt-IN notifications USBTMC devices can use an optional interrupt endpoint for notification messages. These typically contain two-byte headers indicating the payload format, but the driver does not check if these headers are present before accessing the data buffers. In cases where the URB actual_length is not enough to fit these headers, the driver will either cause an out-of-bounds read, or consume stale leftover data from a previous notification. Fix by checking if actual_data contains enough bytes for the headers, otherwise resubmit URB to the interrupt endpoint.

CVE-2026-63904CVE identifier
7.1CVSS 3.1 base score (high)
0.2%EPSS: chance of exploitation in the next 30 days (higher than 7% of CVEs)
2026-07-19published

What do these terms mean? CVE · CVSS score · exploited (KEV) · EPSS · backported fix · all terms

What to do now

Check whether you run Linux kernel and which version (commands below).
Install the fixed version for your system: see “Patch it” below.
Reboot into the new kernel (uname -r to confirm); live patching (kpatch, Ubuntu Livepatch, SUSE kGraft/klp) can defer the reboot for some CVEs

Affected and fixed versions

Affected:

Linux Linux dbf3e7f654c0f06a932b8fcafac78de9d0b81d68 to before e794bd67b3faf98af46f958897f6b91412c7d2a9
Linux Linux dbf3e7f654c0f06a932b8fcafac78de9d0b81d68 to before e3eec3005de44e7f37d8d7724be636446516ab42
Linux Linux dbf3e7f654c0f06a932b8fcafac78de9d0b81d68 to before ae87f505917e703ae3b487d9663d78826ff43608
Linux Linux dbf3e7f654c0f06a932b8fcafac78de9d0b81d68 to before 5de7df75ef3a2756b25fe3d582a4a2970444fe5a
Linux Linux dbf3e7f654c0f06a932b8fcafac78de9d0b81d68 to before 69020fa089f1bf0e1a10a15265f31b143a846409
Linux Linux dbf3e7f654c0f06a932b8fcafac78de9d0b81d68 to before 75f6d3da2cc646983f41807ef98851569c12bca9
Linux Linux dbf3e7f654c0f06a932b8fcafac78de9d0b81d68 to before f141b01eaa58ac7e323931d670318aa247bff087
Linux Linux dbf3e7f654c0f06a932b8fcafac78de9d0b81d68 to before 52f2ad3f7e5eb3b5908e1d685d4342519dc9cfcd
Linux Linux 4.6

Patch it

Use the commands for your system. Distribution packages often keep an older version number with the fix backported, so compare with the fixed package versions in the table below, not only with the upstream version.

Debian

sudo apt update
sudo apt install --only-upgrade linux-image-amd64

Ubuntu

sudo apt update
sudo apt install --only-upgrade linux-image-generic (or the installed flavour: linux-image-aws, -azure, -gcp, -virtual)

RHEL, AlmaLinux, Rocky, Oracle

sudo dnf upgrade --refresh kernel

Fedora

sudo dnf upgrade --refresh kernel

SUSE / openSUSE

sudo zypper refresh
sudo zypper update kernel-default

Amazon Linux

sudo dnf upgrade --releasever=latest kernel kernel6.12

Arch Linux

sudo pacman -Syu

Alpine

apk update && apk upgrade linux-lts linux-virt

FreeBSD

not Linux

General update steps for every system are on the Linux and Unix & BSD pages; after updating, see which services to restart.

Fix status in Linux distributions

Release	Package	Status	Fixed version / advisory
Debian 12	`linux`	fixed	`6.1.176-1`
Debian 13	`linux`	fixed	`6.12.94-1`
Debian testing	`linux`	fixed	`7.0.12-1`
Red Hat Enterprise Linux 9	`kernel`	fix deferred
Red Hat Enterprise Linux 9	`kernel-rt`	fix deferred
Red Hat Enterprise Linux 8	`kernel`	fix deferred
Red Hat Enterprise Linux 8	`kernel-rt`	fix deferred
Red Hat Enterprise Linux 7	`kernel`	fix deferred
Red Hat Enterprise Linux 7	`kernel-rt`	fix deferred
Red Hat Enterprise Linux 6	`kernel`	out of support scope
Red Hat Enterprise Linux 10	`kernel`	fix deferred

From the Debian security tracker, Ubuntu CVE tracker and Red Hat Security Data API, refreshed every few hours.

Sources

Page generated automatically from official sources on 2026-11-03 18:05 UTC. Always confirm with your vendor's advisory.