CVE-2026-97576

A flaw was found in the Linux kernel's Video4Linux2 (V4L2) subsystem. A local attacker can exploit this flaw by submitting a crafted High Efficiency Video Coding (HEVC) control structure with tile counts that exceed array limits. Because the kernel fails to validate these bounds properly, this issue can lead to an out-of-bounds memory read, resulting in a system crash and Denial of Service (DoS).

A moderate severity flaw was found in the Linux kernel's Video4Linux2 (V4L2) subsystem. The compound-control validation performed by std_validate_compound() did not bound the High Efficiency Video Coding (HEVC) picture parameter set (PPS) tile counts, num_tile_columns_minus1 and num_tile_rows_minus1, against the capacity of the column_width_minus1[] and row_height_minus1[] uAPI arrays. A local attacker with access to a V4L2 stateless HEVC decoding device could submit a crafted V4L2_CTRL_TYPE_HEVC_PPS control with tiling enabled and tile counts exceeding the array capacity; stateless HEVC decoder drivers would then read beyond those arrays and use the invalid values as tile-loop bounds, causing an out-of-bounds read that can crash the kernel and result in denial of service.

Red Hat Enterprise Linux 8 and earlier streams, including the RHEL 6, 7, and 8 kernels (and kernel-rt where shipped) and OpenShift Container Platform versions shipping RHEL 8 based CoreOS, are not affected because the vulnerable code is not present. Red Hat Enterprise Linux 9 and 10 (kernel and kernel-rt), Red Hat In-Vehicle OS, and OpenShift Container Platform versions built on RHEL 9 based CoreOS are affected, with fixes deferred to future planned updates given the moderate severity and local, availability-only impact of this issue. The residual risk is that a local user with access to a V4L2 stateless HEVC decode device node can trigger a kernel crash and denial of service.

Red Hat rates this flaw Moderate with a CVSS 3.1 base score of 5.5 (AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H). This differs from the upstream CVE.org severity of Important (7.8, C:H/I:H/A:H) because the out-of-bounds read values are consumed internally by the decoder drivers as loop bounds and are not disclosed to user space, limiting the impact to availability rather than confidentiality or integrity.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Exploitation requires local access to a V4L2 stateless HEVC decoding device node. As a workaround, restrict access to video device nodes (for example /dev/video*) to trusted users only, for instance by removing untrusted users from the video group or otherwise limiting permissions on the device nodes, so that unprivileged local users cannot submit the crafted HEVC PPS control structures that trigger this flaw.