CVE-2026-84447 Denial of service in libheif
Crafted HEIF/AVIF files can cause excessive CPU and memory usage in libheif, leading to denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-84447?
CVE-2026-84447 is a high-severity denial of service vulnerability in strukturag libheif, published on 18 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
libheif is a HEIF and AVIF file format decoder and encoder. In 1.23.1 and earlier, crafted grid, iovl, and iden reference graphs can repeatedly decode the same base image because processed_ids is copied per branch and ImageItem::decode_image() has no shared operation budget. This vulnerability is fixed in 1.23.2.
Weakness: CWE-770
Which versions are affected by CVE-2026-84447?
How do I fix CVE-2026-84447?
Upgrade to a fixed version.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-84447 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-84447 exists.
Sources
Also known as BELL-CVE-2026-84447, DEBIAN-CVE-2026-84447, ECHO-780c-8092-a9bc, GHSA-x8xm-cm2c-cfc8, MINI-jm44-m948-pxc4, ROOT-OS-DEBIAN-12-CVE-2026-84447 and 1 more.