FFmpeg before 9.0 has a signed integer overflow in libavformat/mov.c. In mov_read_ispe(), uint32_t width/height values from a crafted HEIF ispe box are stored into signed int fields without bounds checking, allowing values exceeding INT_MAX to become negative. In read_image_grid(), accumulating these values causes signed integer overflow (undefined behavior per C17 section 6.5), which on x86 wraps to a small positive value, bypassing downstream validity checks.
| Version | Score | Severity | Vector String |
|---|---|---|---|
| 3.1 | 6.9 | Medium | CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L |