Vulnerability · Published Sep 18, 2026 · Assigned by GitHub_M
CVE-2026-84384libheif: brotli/zlib decompression paths lack output-size limits, allowing decompression-bomb OOM/DoS
High 7.5
In plain English
A high-severity security flaw in libheif from strukturag. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 44% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | libheif | no fix listed | DEBIAN-CVE-2026-84384 |
| Debian:13 | libheif | 1.23.4-1~deb13u1 | DEBIAN-CVE-2026-84384 |
| Debian:14 | libheif | 1.23.2-1 | DEBIAN-CVE-2026-84384 |
| Ubuntu:24.04:LTS | libheif | 1.17.6-1ubuntu4.9 | USN-8846-1 |
| Ubuntu:24.04:LTS | libheif | 1.17.6-1ubuntu4.9 | UBUNTU-CVE-2026-84384 |
| Ubuntu:26.04:LTS | libheif | 1.21.2-3ubuntu0.6 | USN-8846-1 |
| Ubuntu:26.04:LTS | libheif | 1.21.2-3ubuntu0.6 | UBUNTU-CVE-2026-84384 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| strukturag | libheif | >= 1.19.0, < 1.23.2 |
Weakness: CWE-409 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H