CVE-2026-63957: USB: serial: safe_serial: fix memory corruption with small endpoint

High 7.8 EPSS 0.2% Linux kernel

In the Linux kernel, the following vulnerability has been resolved: USB: serial: safe_serial: fix memory corruption with small endpoint Make sure that the bulk-out buffer size is at least eight bytes to avoid user-controlled slab corruption in "safe" mode should a malicious device report a smaller size.

CVE-2026-63957CVE identifier
7.8CVSS 3.1 base score (high)
0.2%EPSS: chance of exploitation in the next 30 days (higher than 6% 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 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before e3a1d6eee25dc96b1d2db0ecd9d8741e92056476
Linux Linux 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before c7336c0fba5c959249f3d793d33076b992ec3ee4
Linux Linux 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 161ea0e5236f5f051d2d85d6c54dd08ee9dc7ba4
Linux Linux 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 9b3145b3001fb24de1da72d1deb0bea70e5a078b
Linux Linux 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before a550ed2117ca4709d38f713933ff924a83942e41
Linux Linux 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before f793b67d41e5fab719c5a90baa77cbd2fe259517
Linux Linux 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 857b3cc73f91871ae4433f8b97c4670b78f8dc96
Linux Linux 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 438061ed1ad85e6743e2dce826671772d81089ec
Linux Linux 2.6.12

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`	affected
Red Hat Enterprise Linux 9	`kernel-rt`	affected
Red Hat Enterprise Linux 8	`kernel`	affected
Red Hat Enterprise Linux 8	`kernel-rt`	affected
Red Hat Enterprise Linux 7	`kernel`	affected
Red Hat Enterprise Linux 7	`kernel-rt`	affected
Red Hat Enterprise Linux 6	`kernel`	out of support scope
Red Hat Enterprise Linux 10	`kernel`	affected

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.