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Fencer Vulns
high 7.8

CVE-2026-89894 json

media: cx231xx: reject geometry changes while the VBI queue is busy

published 2026-09-16 54 d ago modified 2026-10-19 21 d ago also EUVD-2026-80494

cvss
7.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 6%
public exploits
0
none known

Summary

In the Linux kernel, the following vulnerability has been resolved:

media: cx231xx: reject geometry changes while the VBI queue is busy

vidioc_s_fmt_vid_cap() and vidioc_s_std() change the device-wide dev->width / dev->norm but only refuse the change when the *video* queue (dev->vidq) is busy. The VBI queue (dev->vbiq) shares that same geometry: cx231xx_init_vbi_isoc() latches dma_q->lines_per_field from dev->norm, the VBI videobuf2 plane is sized from dev->width / dev->norm in vbi_queue_setup() and vbi_buf_prepare(), and cx231xx_do_vbi_copy() then recomputes the destination offset from the *live* dev->width and the latched lines_per_field on every URB completion:

offset = lines_completed * (dev->width << 1) + ...; if (dma_q->current_field == 2) offset += dev->width * 2 * dma_q->lines_per_field; memcpy(plane + offset, p_buffer, lencopy);

Because the VBI node shares video_ioctl_ops with the video node, an application can size a small VBI plane (REQBUFS/QBUF with a small width, or with the NTSC standard), then enlarge dev->width (or switch dev->norm to PAL) through the video node while the VBI stream is running -- the change is allowed because only dev->vidq is checked -- and let the device deliver a field-2 VBI payload. cx231xx_do_vbi_copy() now computes the offset with the larger geometry and memcpy()s past the end of the smaller plane that was already allocated, a heap out-of-bounds write whose offset is attacker-chosen and whose contents come from the device. The per-field guard in cx231xx_copy_vbi_line() does not help: it bounds the copy against the latched lines_per_field, not the plane's real capacity, and vb2 does not re-run buf_prepare() for an already prepared buffer.

Refuse the format/standard change when the VBI queue is busy as well, so the geometry cannot change underneath an allocated VBI buffer.

Patch / fix

  • Linux Linux 5.10.270, 5.15.221, 6.1.188, 6.6.157, 6.12.110, 6.18.51, 7.2.5, 7.3
  • linux Debian 12 6.1.190-1
  • linux Debian 13 6.12.111-1
  • linux Debian 14 7.2.6-1
  • linux-6.12 Debian 12 6.12.111-1~deb12u1

debian advisories DEBIAN-CVE-2026-89894

  • linux Ubuntu 22.04 LTS 5.15.0-202.212
  • linux Ubuntu 26.04 LTS 7.0.0-42.42
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1119.126
  • linux-aws Ubuntu 26.04 LTS 7.0.0-1016.17
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1120.130
  • linux-gcp Ubuntu 26.04 LTS 7.0.0-1016.18
  • linux-gke Ubuntu 22.04 LTS 5.15.0-1115.121
  • linux-ibm Ubuntu 22.04 LTS 5.15.0-1113.117

ubuntu advisories UBUNTU-CVE-2026-89894

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • kernel RHEL 10.2 6.12.0-211.66.1.el10_2
  • rv RHEL 10.2 6.12.0-211.66.1.el10_2
  • perf RHEL 10.2 6.12.0-211.66.1.el10_2
  • rtla RHEL 10.2 6.12.0-211.66.1.el10_2
  • libperf RHEL 10.2 6.12.0-211.66.1.el10_2
  • kernel-rt RHEL 10.2 6.12.0-211.66.1.el10_2
  • kernel-64k RHEL 10.2 6.12.0-211.66.1.el10_2
  • kernel-core RHEL 10.2 6.12.0-211.66.1.el10_2

red hat advisories RHSA-2026:83207RHSA-2026:81552

  • kernel-source Linux Micro 6.0 6.4.0-159998.55.1
  • kernel-default Linux Micro 6.0 6.4.0-159998.55.1
  • kernel-kvmsmall Linux Micro 6.0 6.4.0-159998.55.1
  • kernel-default-base Linux Micro 6.0 6.4.0-159998.55.1.159998.21.42
  • kernel-64kb SLE Module for Basesystem 15 SP7 6.4.0-150700.53.90.1
  • kernel-syms SLE Module for Development Tools 15 SP7 6.4.0-150700.53.90.1
  • kernel-azure SLE Module for Public Cloud 15 SP7 6.4.0-150700.53.90.1
  • kernel-source SLE Module for Development Tools 15 SP7, SLE Module for Basesystem 15 SP7 6.4.0-150700.53.90.1

suse advisories SUSE-SU-2026:24550-1SUSE-SU-2026:5091-1

  • kernel-source openSUSE Tumbleweed 7.2.7-1.1

opensuse advisories openSUSE-SU-2026:11880-1

  • kernel AlmaLinux 10 6.12.0-211.66.1.el10_2
  • rv AlmaLinux 10 6.12.0-211.66.1.el10_2
  • perf AlmaLinux 10 6.12.0-211.66.1.el10_2
  • rtla AlmaLinux 10 6.12.0-211.66.1.el10_2
  • libperf AlmaLinux 10 6.12.0-211.66.1.el10_2
  • kernel-rt AlmaLinux 10 6.12.0-211.66.1.el10_2
  • kernel-64k AlmaLinux 10 6.12.0-211.66.1.el10_2
  • kernel-core AlmaLinux 10 6.12.0-211.66.1.el10_2

almalinux advisories ALSA-2026:83207ALSA-2026:81552

  • kernel Rocky Linux 10 6.12.0-211.66.1.el10_2
  • kernel Rocky Linux 9 5.14.0-687.57.1.el9_8

rocky linux advisories RLSA-2026:83207RLSA-2026:81552

  • kernel Azure Linux 3.0 6.6.157.1-1

azure linux advisories AZL-101478

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-89894 updated cvss 7.0

kernel: media: cx231xx: reject geometry changes while the VBI queue is busy

  • Red Hat Enterprise Linux 9 kernel-rt, kernel-rt-kvm, kernel-rt-core, kernel-rt-modules, kernel-rt-debug-kvm, kernel-rt-debug-core, +12 more Red Hat OpenShift Container Platform 5 openshift/ose-rhel-coreos-9
    affected: workaround, no fix available
  • Red Hat Enterprise Linux kernel-modules-internal 6.12.0-211.66.1.el10_2
    fixed: vendor fix RHSA-2026:83207
  • Red Hat Enterprise Linux AppStream (v. 9) rv 5.14.0-687.57.1.el9_8, perf 5.14.0-687.57.1.el9_8, rtla 5.14.0-687.57.1.el9_8, python3-perf 5.14.0-687.57.1.el9_8, kernel-devel-matched 5.14.0-687.57.1.el9_8, kernel-64k-devel-matched 5.14.0-687.57.1.el9_8, +7 more
    fixed: vendor fix RHSA-2026:81552
  • Red Hat Enterprise Linux AppStream (v. 10) rv 6.12.0-211.66.1.el10_2, perf 6.12.0-211.66.1.el10_2, rtla 6.12.0-211.66.1.el10_2, python3-perf 6.12.0-211.66.1.el10_2, kernel-devel-matched 6.12.0-211.66.1.el10_2, kernel-64k-devel-matched 6.12.0-211.66.1.el10_2, +7 more
    fixed: vendor fix RHSA-2026:83207
  • Red Hat Enterprise Linux BaseOS (v. 9) kernel 5.14.0-687.57.1.el9_8, kernel-64k 5.14.0-687.57.1.el9_8, kernel-core 5.14.0-687.57.1.el9_8, kernel-tools 5.14.0-687.57.1.el9_8, kernel-modules 5.14.0-687.57.1.el9_8, kernel-64k-core 5.14.0-687.57.1.el9_8, +27 more
    fixed: vendor fix RHSA-2026:81552
  • Red Hat Enterprise Linux BaseOS (v. 10) kernel 6.12.0-211.66.1.el10_2, kernel-64k 6.12.0-211.66.1.el10_2, kernel-core 6.12.0-211.66.1.el10_2, kernel-tools 6.12.0-211.66.1.el10_2, kernel-modules 6.12.0-211.66.1.el10_2, kernel-64k-core 6.12.0-211.66.1.el10_2, +28 more
    fixed: vendor fix RHSA-2026:83207
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) libperf 5.14.0-687.57.1.el9_8, kernel-debuginfo-common-s390x 5.14.0-687.57.1.el9_8, kernel-debuginfo-common-x86_64 5.14.0-687.57.1.el9_8, kernel-debuginfo-common-aarch64 5.14.0-687.57.1.el9_8, kernel-debuginfo-common-ppc64le 5.14.0-687.57.1.el9_8
    fixed: vendor fix RHSA-2026:81552
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) libperf 6.12.0-211.66.1.el10_2, kernel-debuginfo-common-s390x 6.12.0-211.66.1.el10_2, kernel-debuginfo-common-x86_64 6.12.0-211.66.1.el10_2, kernel-debuginfo-common-aarch64 6.12.0-211.66.1.el10_2, kernel-debuginfo-common-ppc64le 6.12.0-211.66.1.el10_2 Red Hat Enterprise Linux Hidden (v. 10) kernel-modules-internal 6.12.0-211.66.1.el10_2, kernel-debuginfo-common-x86_64 6.12.0-211.66.1.el10_2
    fixed: vendor fix RHSA-2026:83207
show 6 more
  • Red Hat Enterprise Linux Real Time (v. 9) kernel-rt 5.14.0-687.57.1.el9_8, kernel-rt-64k 5.14.0-687.57.1.el9_8, kernel-rt-core 5.14.0-687.57.1.el9_8, kernel-rt-modules 5.14.0-687.57.1.el9_8, kernel-rt-64k-core 5.14.0-687.57.1.el9_8, kernel-rt-debug-core 5.14.0-687.57.1.el9_8, +14 more
    fixed: vendor fix RHSA-2026:81552
  • Red Hat Enterprise Linux Real Time (v. 10) kernel-rt 6.12.0-211.66.1.el10_2, kernel-rt-64k 6.12.0-211.66.1.el10_2, kernel-rt-core 6.12.0-211.66.1.el10_2, kernel-rt-modules 6.12.0-211.66.1.el10_2, kernel-rt-64k-core 6.12.0-211.66.1.el10_2, kernel-rt-debug-core 6.12.0-211.66.1.el10_2, +14 more
    fixed: vendor fix RHSA-2026:83207
  • Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt 5.14.0-687.57.1.el9_8, kernel-rt-core 5.14.0-687.57.1.el9_8, kernel-rt-modules 5.14.0-687.57.1.el9_8, kernel-rt-debug-core 5.14.0-687.57.1.el9_8, kernel-rt-modules-core 5.14.0-687.57.1.el9_8, kernel-rt-debug-modules 5.14.0-687.57.1.el9_8, +4 more
    fixed: vendor fix RHSA-2026:81552
  • Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt 6.12.0-211.66.1.el10_2, kernel-rt-core 6.12.0-211.66.1.el10_2, kernel-rt-modules 6.12.0-211.66.1.el10_2, kernel-rt-debug-core 6.12.0-211.66.1.el10_2, kernel-rt-modules-core 6.12.0-211.66.1.el10_2, kernel-rt-debug-modules 6.12.0-211.66.1.el10_2, +4 more
    fixed: vendor fix RHSA-2026:83207
  • Red Hat OpenShift Container Platform 4.22 rhcos 4.22.9.8.202610241758
    fixed: vendor fix RHSA-2026:89197
  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-8
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.17% chance of exploitation in the next 30 days, higher than 6% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products

  • Linux Linux

Classification

Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.