Linux Kernel up to 7.2.4 cx231xx vidioc_s_fmt_vid_cap/vidioc_s_std out-of-bounds write

CVSS Meta Temp Score
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4.2$0-$5k0.00

Summaryinfo

A vulnerability labeled as problematic has been found in Linux Kernel up to 7.2.4. The affected element is the function vidioc_s_fmt_vid_cap/vidioc_s_std of the component cx231xx. Executing a manipulation can lead to out-of-bounds write. This vulnerability is registered as CVE-2026-89894. The attack needs to be launched locally. No exploit is available. The affected component should be upgraded.

Detailsinfo

A vulnerability classified as problematic was found in Linux Kernel up to 7.2.4. This vulnerability affects the function vidioc_s_fmt_vid_cap/vidioc_s_std of the component cx231xx. The manipulation with an unknown input leads to a out-of-bounds write vulnerability. The CWE definition for the vulnerability is CWE-787. The product writes data past the end, or before the beginning, of the intended buffer. As an impact it is known to affect integrity, and availability. CVE summarizes:

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.

The advisory is available at git.kernel.org. This vulnerability was named CVE-2026-89894 since 09/11/2026. The exploitation appears to be easy. Local access is required to approach this attack. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 09/16/2026).

Upgrading to version 5.10.270, 5.15.221, 6.1.188, 6.6.157, 6.12.110, 6.18.51, 7.2.5 or 7.3-rc1 eliminates this vulnerability. Applying the patch aa3314506deb9703bcf0e889db08959440228fbf/90d50648af36a1fbf5dbc99238de6fd0e58a13e0/a5dd3d7fba358ff9486f3f51b2a9038348c0970a/54ac6df8b8d97eddc3ae97fd2045bdedc8541b6d/1d1079db8d1807e259a1d2679ed314949797aad9/7087bef6510c7df5df0b19192633b8ecc0f33a6f/a636c72c7f522d984fa498fc0631f33a2d0be3fd/627a121c15fe05a541f44d86016294b80bada75d is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 4.4
VulDB Meta Temp Score: 4.2

VulDB Base Score: 4.4
VulDB Temp Score: 4.2
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Out-of-bounds write
CWE: CWE-787 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: No

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 5.10.270/5.15.221/6.1.188/6.6.157/6.12.110/6.18.51/7.2.5/7.3-rc1
Patch: aa3314506deb9703bcf0e889db08959440228fbf/90d50648af36a1fbf5dbc99238de6fd0e58a13e0/a5dd3d7fba358ff9486f3f51b2a9038348c0970a/54ac6df8b8d97eddc3ae97fd2045bdedc8541b6d/1d1079db8d1807e259a1d2679ed314949797aad9/7087bef6510c7df5df0b19192633b8ecc0f33a6f/a636c72c7f522d984fa498fc0631f33a2d0be3fd/627a121c15fe05a541f44d86016294b80bada75d

Timelineinfo

09/11/2026 CVE reserved
09/16/2026 +5 days Advisory disclosed
09/16/2026 +0 days VulDB entry created
09/16/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-89894 (🔒)
GCVE (CVE): GCVE-0-2026-89894
GCVE (VulDB): GCVE-100-405730

Entryinfo

Created: 09/16/2026 14:18
Changes: 09/16/2026 14:18 (59)
Complete: 🔍
Cache ID: 216::103

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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