Vulnerability is in a Vulkan HEVC decoder code path that does not exist
in this version.
Refs:
- https://security-tracker.debian.org/tracker/CVE-2026-64831
details: |
The vulnerable code (a stack-allocated VPS/SPS parameter struct built
per-frame in vk_hevc_end_frame(), overflowed by an unchecked
vps_num_hrd_parameters) was introduced by upstream commit 82864c21
("vulkan_hevc: use VK_KHR_video_maintenance2 if available", 2026-03-14)
as part of a refactor that is not present in the 7.1.x branch. In this
source, vk_hevc_end_frame() has no such stack buffer: VPS HRD
parameters are built once into a heap buffer in
alloc_hevc_header_structs()/set_vps(), whose destination arrays are
bounded by HEVC_MAX_LAYER_SETS (1024), and vps_num_hrd_parameters is
already bounded by vps_num_layer_sets (<=1024) at parse time in
libavcodec/hevc/ps.c. The CVE's own affected-version range ("FFmpeg
8.0 through 8.1.2") is consistent with this. If this spec is ever
bumped to >=8.0, this entry MUST be re-evaluated and likely converted
into a real patch.