data built 2026-10-19T13:16:53Z

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CVE-2026-90063

virtio-net: Ensure that TCP packets don't overflow gso_segs

EPSS 0.2%

Published 2026-09-17 (31 days ago) by the Linux kernel CNA. Subsystem include/linux. Debian urgency: not yet assigned.

What to do, per Debian release

Debian's own status for CVE-2026-90063 in every release this site tracks, and what each one means in practice. Every status below is the one the Debian Security Team publishes for this CVE. source

ReleaseStatus VersionWhat this means
Debian 12bookwormfixedDLA-4841-1 · 2026-10-17 · text6.1.190-1Update the kernel and reboot. DLA-4841-1 shipped the fix on 2026-10-17, in 6.1.190-1. A running kernel keeps the old code until the machine restarts.
Debian 13trixiefixedDSA-6528-1 · 2026-09-29 · text6.12.111-1Update the kernel and reboot. DSA-6528-1 shipped the fix on 2026-09-29, in 6.12.111-1. A running kernel keeps the old code until the machine restarts.
Debian 14forkyfixed7.2.6-1Update the kernel and reboot. Fixed in 7.2.6-1. A running kernel keeps the old code until the machine restarts.
Debian unstablesidfixed7.2.6-1Update the kernel and reboot. Fixed in 7.2.6-1. A running kernel keeps the old code until the machine restarts.
Debian 12bookworm · linux-6.12fixedDLA-4817-1 · 2026-10-04 · text6.12.111-1~deb12u1Update the kernel and reboot. DLA-4817-1 shipped the fix on 2026-10-04, in 6.12.111-1~deb12u1. A running kernel keeps the old code until the machine restarts.

The vulnerability

What the bug is

The user can specify any gso_size in a packet crafted with an AF_PACKET PACKET_VNET_HDR socket, even smaller than TCP_MIN_GSO_SIZE = 8. At the same time, GSO_MAX_SIZE = 8 * GSO_MAX_SEGS = 8 * 65535. When the user crafts a packet with gso_size < 8, there is a risk for partial GSO to overflow the 16-bit gso_segs field when dividing the SKB length by gso_size. Adjust gso_size of TCP packets to be at least TCP_MIN_GSO_SIZE = 8. Keep gso_size of UDP GSO packets, as gso_size=1 is valid and explicitly tested at tools/testing/selftests/net/tun.c:649.

Where it lives

The fix touches these files. If the subsystem is one you do not use, the practical exposure is lower, though the package is still the vulnerable one.

include/linux/virtio_net.h

What this is
VIRTIO NET DRIVERMAINTAINERS section matched on include/linux/virtio_net.h · netdev@vger.kernel.org · Maintained
Show whether Debian builds this, per release

Not established. This site could not find the build rule for the affected file in the kernel trees Debian ships, so it has no answer about whether Debian compiles this code. Read that as unknown, never as absent.

  • bookworm, trixie, forky, sid, bookworm · linux-6.12?
?
not established - no Makefile entry for the affected file

Where a release above reads "not established", no build rule for the affected file was found in that release's kernel tree. That is a gap in this lookup, not a finding that the code is absent.

From the configuration Debian publishes for every kernel flavour it builds. It covers only the architectures Debian ships a linux-config package for, and nothing about a kernel you built yourself. Debian's own status above stays authoritative about the source package.MAINTAINERS

Signals

Published
2026-09-17 (31 days ago)source
CVSS
no vector published, unrated
Attack vector
not published
EPSS
0.21%, higher than 10.7% of all CVEssource
CISA KEV
not listedthe KEV catalogue
Debian urgency
not yet assignedsource
Subsystem
include/linux

Upstream fixes

The versions the CNA records as introducing and fixing this, and the commit for each. source

IntroducedFixed inCommit
5.75.15.221d3d111fe8097
5.76.1.1888f6667a08188
5.76.6.157339f47ae04dc
5.76.12.11029bd12c7c5f9
5.76.18.520e5ed3b98d1d
5.77.2.675c271c48f48
5.77.3c27c449d455a
4.14.18700
4.19.13100
5.4.4600
5.6.1800

Debian advisories

AdvisoryDateShipped toDebian
DLA-4841-12026-10-17bookworm 6.1.190-1tracker
DLA-4817-12026-10-04bookworm 6.12.111-1~deb12u1tracker
DSA-6528-12026-09-29trixie 6.12.111-1tracker

Why the CNA scored it this way

The kernel CNA published no CVSS vector and no reasoning for CVE-2026-90063, which is why it is shown as unrated rather than given an invented score. 6,405 of the 20,413 CVEs here carry reasoning; this is not one of them.