CVE-2026-84384 libheif: brotli/zlib decompression paths lack output-size limits, allowing decompression-bomb OOM/DoS
Crafted HEIF or AVIF files can cause unbounded memory consumption in libheif, leading to application crashes via decompression bombs.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-84384?
CVE-2026-84384 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. From 1.19.0 until 1.23.2, crafted HEIF or AVIF mime metadata and unci image data can cause decompress_brotli() and do_inflate() to grow accumulated output without an effective size limit or MemoryHandle accounting. The brotli path has no output bound, while the zlib path checks only a small temporary buffer in a branch that valid streams do not reach, and overlapping icef units can decompress the same payload repeatedly. HeifContext::interpret_heif_file_images() processes multiple compressed metadata items during file opening, allowing a small file to consume unbounded memory and terminate the process. This issue is fixed in version 1.23.2.
Weakness: CWE-409
Which versions are affected by CVE-2026-84384?
How do I fix CVE-2026-84384?
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-2026-84384 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-84384 exists.
Sources
Also known as BELL-CVE-2026-84384, DEBIAN-CVE-2026-84384, ECHO-0bbf-2ab0-3791, GHSA-24wx-9w62-c96w, MINI-65hh-jw4r-jqr9, ROOT-OS-DEBIAN-12-CVE-2026-84384 and 1 more.