This vulnerability involves an out-of-bounds write in GStreamer's H.266/VVC PPS picture partition parser within the gst-plugins-bad package on Red Hat Enterprise Linux 10. Specifically, the function gst_h266_parser_parse_picture_partition() iterates over slices without verifying that the slice index remains within the bounds of three fixed-size arrays (slice_height_in_ctus, slice_top_left_ctu_x, slice_top_left_ctu_y) in the GstH266PPS structure. This can lead to writes beyond the allocated memory for these arrays. The initial proof-of-concept demonstrated a 4-byte out-of-bounds write, but the code logic allows for larger out-of-bounds writes across multiple iterations. Exploitation requires processing a specially crafted H.266/VVC media file.

The vulnerability allows an attacker to cause an out-of-bounds write in memory when processing a malicious H.266/VVC media file. According to the CVSS vector, this can lead to a denial of service (application crash or instability) but does not impact confidentiality or integrity. The attack vector is network-based and requires user interaction to trigger (e.g., opening or streaming a crafted media file). No known exploits in the wild have been reported.

Patch status is not yet confirmed — check the Red Hat advisory at https://access.redhat.com/security/cve/CVE-2026-53701 for current remediation guidance. Until a patch is available, avoid processing untrusted H.266/VVC media files with the affected GStreamer component. No official fix or workaround is currently documented in the provided advisory content.