Vulnerability · Published Sep 18, 2026 · Assigned by GitHub_M
CVE-2026-84444libheif uncompressed tiled image encoding allows out-of-bounds write
High 7.4
In plain English
A high-severity out-of-bounds write 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 41% 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. Prior to 1.23.2, when WITH_UNCOMPRESSED_CODEC is enabled, heif_context_add_image_tile() accepts an independently constructed tile whose component-plane dimensions do not match the tile geometry established by the prototype image. ImageItem_uncompressed::add_image_tile() passes that tile directly to unc_encoder::encode_tile(), which lacked the check_component_sizes() gate and sizes its output from the configured tile geometry while copying the tile's actual component-plane dimensions. An oversized component plane can therefore make unc_encoder_component_interleave::encode_tile() copy attacker-controlled data beyond the heap output buffer. 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-2026-84444 |
| Debian:13 | libheif | 1.23.4-1~deb13u1 | DEBIAN-CVE-2026-84444 |
| Debian:14 | libheif | 1.23.2-1 | DEBIAN-CVE-2026-84444 |
| Ubuntu:24.04:LTS | libheif | no fix listed | UBUNTU-CVE-2026-84444 |
| Ubuntu:26.04:LTS | libheif | no fix listed | UBUNTU-CVE-2026-84444 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| strukturag | libheif | < 1.23.2 |
Weakness: CWE-787 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H