libheif vulnerabilities

USN-8526-1 fixed vulnerabilities in libheif. This update provides the
corresponding updates for CVE-2026-47709 and CVE-2026-47714 in
Ubuntu 24.04 LTS.

Original advisory details:

Junyi Liu discovered that libheif had a null pointer dereference in its
image tiling interface. An attacker could possibly use this issue to
cause a denial of service. (CVE-2026-47709)

Calvin Young and Enoch Chow discovered that libheif had an integer
overflow in its inline mask size calculation. An attacker could
possibly use this issue to cause a denial of service or obtain sensitive
information. (CVE-2026-47714)