{"id":"CVE-2026-89894","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nmedia: cx231xx: reject geometry changes while the VBI queue is busy\n\nvidioc_s_fmt_vid_cap() and vidioc_s_std() change the device-wide\ndev->width / dev->norm but only re…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nmedia: cx231xx: reject geometry changes while the VBI queue is busy\n\nvidioc_s_fmt_vid_cap() and vidioc_s_std() change the device-wide\ndev->width / dev->norm but only re…","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","vendor":"Linux","product":"Linux","affected":["Linux >= 7c617138b8254a6bb60bfb5b8fc53eb8b3d6c3ab < aa3314506deb9703bcf0e889db08959440228fbf","Linux >= 7c617138b8254a6bb60bfb5b8fc53eb8b3d6c3ab < 90d50648af36a1fbf5dbc99238de6fd0e58a13e0","Linux >= 7c617138b8254a6bb60bfb5b8fc53eb8b3d6c3ab < a5dd3d7fba358ff9486f3f51b2a9038348c0970a","Linux >= 7c617138b8254a6bb60bfb5b8fc53eb8b3d6c3ab < 54ac6df8b8d97eddc3ae97fd2045bdedc8541b6d","Linux >= 7c617138b8254a6bb60bfb5b8fc53eb8b3d6c3ab < 1d1079db8d1807e259a1d2679ed314949797aad9","Linux >= 7c617138b8254a6bb60bfb5b8fc53eb8b3d6c3ab < 7087bef6510c7df5df0b19192633b8ecc0f33a6f","Linux >= 7c617138b8254a6bb60bfb5b8fc53eb8b3d6c3ab < a636c72c7f522d984fa498fc0631f33a2d0be3fd","Linux >= 7c617138b8254a6bb60bfb5b8fc53eb8b3d6c3ab < 627a121c15fe05a541f44d86016294b80bada75d","Linux 5.5"],"published":"2026-09-16","updated":"2026-09-16","sourceUpdated":"2026-09-16T15:18:15.790","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-89894","references":[{"url":"https://git.kernel.org/stable/c/1d1079db8d1807e259a1d2679ed314949797aad9","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/54ac6df8b8d97eddc3ae97fd2045bdedc8541b6d","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/627a121c15fe05a541f44d86016294b80bada75d","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/7087bef6510c7df5df0b19192633b8ecc0f33a6f","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/90d50648af36a1fbf5dbc99238de6fd0e58a13e0","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/a5dd3d7fba358ff9486f3f51b2a9038348c0970a","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/a636c72c7f522d984fa498fc0631f33a2d0be3fd","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/aa3314506deb9703bcf0e889db08959440228fbf","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89894.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-89894"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2535338"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89894"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89894"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89894.mbox"},{"url":"https://access.redhat.com/errata/RHSA-2026:83207"},{"url":"https://access.redhat.com/errata/RHSA-2026:81552"}],"tags":["nvd","cve.org","csaf","vex","red-hat"],"ingestedAt":"2026-09-16T10:53:53.981Z","epss":0.00169,"epssPercentile":0.06187,"patched":["10base_smtv","enterprise_linux_appstream_v_10","enterprise_linux_appstream_v_9","enterprise_linux_baseos_v_10","enterprise_linux_baseos_v_9","enterprise_linux_codeready_linux_builder_v_10","enterprise_linux_codeready_linux_builder_v_9","enterprise_linux_hidden_v_10","enterprise_linux_real_time_for_nfv_v_10","enterprise_linux_real_time_for_nfv_v_9","enterprise_linux_real_time_v_10","enterprise_linux_real_time_v_9"],"cwe":["CWE-787"],"scores":{"nvd":7.8,"vendor":7,"cna":7.8},"slug":"CVE-2026-89894","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nmedia: cx231xx: reject geometry changes while the VBI queue is busy\n\nvidioc_s_fmt_vid_cap() and vidioc_s_std() change the device-wide\ndev->width / dev->norm but only refuse the change when the *video* queue\n(dev->vidq) is busy. The VBI queue (dev->vbiq) shares that same geometry:\ncx231xx_init_vbi_isoc() latches dma_q->lines_per_field from dev->norm,\nthe VBI videobuf2 plane is sized from dev->width / dev->norm in\nvbi_queue_setup() and vbi_buf_prepare(), and cx231xx_do_vbi_copy() then\nrecomputes the destination offset from the *live* dev->width and the\nlatched lines_per_field on every URB completion:\n\n\toffset = lines_completed * (dev->width << 1) + ...;\n\tif (dma_q->current_field == 2)\n\t\toffset += dev->width * 2 * dma_q->lines_per_field;\n\tmemcpy(plane + offset, p_buffer, lencopy);\n\nBecause the VBI node shares video_ioctl_ops with the video node, an\napplication can size a small VBI plane (REQBUFS/QBUF with a small width,\nor with the NTSC standard), then enlarge dev->width (or switch dev->norm\nto PAL) through the video node while the VBI stream is running -- the\nchange is allowed because only dev->vidq is checked -- and let the device\ndeliver a field-2 VBI payload. cx231xx_do_vbi_copy() now computes the\noffset with the larger geometry and memcpy()s past the end of the smaller\nplane that was already allocated, a heap out-of-bounds write whose offset\nis attacker-chosen and whose contents come from the device. The\nper-field guard in cx231xx_copy_vbi_line() does not help: it bounds the\ncopy against the latched lines_per_field, not the plane's real capacity,\nand vb2 does not re-run buf_prepare() for an already prepared buffer.\n\nRefuse the format/standard change when the VBI queue is busy as well, so\nthe geometry cannot change underneath an allocated VBI buffer.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **RHSA-2026:83207** · Red Hat · fixed in: 10Base-SMTV, Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux BaseOS (v. 10), Red Hat Enterprise Linux CodeReady Linux Builder (v. 10), Red Hat Enterprise Linux Hidden (v. 10), Red Hat Enterprise Linux Real Time for NFV (v. 10), … · released 2026-10-15 · [advisory](https://access.redhat.com/errata/RHSA-2026:83207)\n- **RHSA-2026:81552** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 9), Red Hat Enterprise Linux BaseOS (v. 9), Red Hat Enterprise Linux CodeReady Linux Builder (v. 9), Red Hat Enterprise Linux Real Time for NFV (v. 9), Red Hat Enterprise Linux Real Time (v. 9) · released 2026-10-13 · [advisory](https://access.redhat.com/errata/RHSA-2026:81552)\n- **Red Hat VEX** · Important · affected: Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-10-15 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89894.json)","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":42.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":205172,"id":"CVE-2026-89894","ts":1789570705577,"field":"cvss","old":null,"new":"7.8"},{"seq":205171,"id":"CVE-2026-89894","ts":1789570705577,"field":"severity","old":"none","new":"high"}]}