# CVE-2026-84444: libheif: libheif is a HEIF and AVIF file format decoder and encoder

CVE-2026-84444 is fixed in libheif on 1 platform, first by DEBIAN-CVE-2026-84444, released September 19, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-84444
- Priority: High
- CVSS: 7.4 (high)
- EPSS: 0.0048
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Sep 18, 2026

## 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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | libheif Debian 13.5 (trixie) | 1.23.4-1~deb13u1 | [DEBIAN-CVE-2026-84444](https://patchblox.com/security/data/fix/linux/debian-cve-2026-84444.md) | Sep 19, 2026 |
| Linux | libheif Debian 14 | 1.23.2-1 | [DEBIAN-CVE-2026-84444](https://patchblox.com/security/data/fix/linux/debian-cve-2026-84444.md) | Sep 19, 2026 |
| Linux | libheif opensuse-leap 16.0 | 1.23.4-160000.1.1 | [OPENSUSE-SU-2026:21889-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21889-1.md) | Sep 20, 2026 |
| Linux | libheif sles 15.7 | 1.23.4-150700.3.21.1 | [SUSE-SU-2026:4276-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-4276-1.md) | Sep 21, 2026 |

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Data as of 2026-11-09T01:18:40Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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