# CVE-2026-84451: libheif: libheif is a HEIF and AVIF file format decoder and encoder

CVE-2026-84451 is fixed in 8 products on 1 platform, first by DEBIAN-CVE-2026-84451, released September 10, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-84451
- Priority: Routine
- CVSS: 6.5 (medium)
- EPSS: 0.0031
- 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. From 1.19.0 until 1.23.3, the no-icef full-item branch of unc_decoder::get_compressed_image_data_uncompressed() in libheif/codecs/uncompressed/unc_decoder.cc retains an addition-based range check that can wrap when a crafted uncompressed tile grid produces a large range_start_offset and range_size. The overflow makes the bounds comparison pass and allows heif_image_handle_decode_image_tile() to call memcpy() with an invalid source pointer and a very large length when decoding a valid high-index advertised tile. This incomplete remediation of CVE-2026-62292 can reliably crash tile-processing applications, while whole-image decoding is not claimed to reach the demonstrated path. This issue is fixed in version 1.23.3.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | heif-pixbuf-loader amzn 2023 | 1.23.4-1.amzn2023 | [ALAS2023-2026-3124](https://patchblox.com/security/data/fix/linux/alas2023-2026-3124.md) | Sep 28, 2026 |
| Linux | heif-pixbuf-loader-debuginfo amzn 2023 | 1.23.4-1.amzn2023 | [ALAS2023-2026-3124](https://patchblox.com/security/data/fix/linux/alas2023-2026-3124.md) | Sep 28, 2026 |
| Linux | libheif Debian 13.5 (trixie) | 1.23.4-1~deb13u1 | [DEBIAN-CVE-2026-84451](https://patchblox.com/security/data/fix/linux/debian-cve-2026-84451.md) | Sep 10, 2026 |
| Linux | libheif Debian 14 | 1.23.3-1 | [DEBIAN-CVE-2026-84451](https://patchblox.com/security/data/fix/linux/debian-cve-2026-84451.md) | Sep 10, 2026 |
| Linux | libheif amzn 2023 | 1.23.4-1.amzn2023 | [ALAS2023-2026-3124](https://patchblox.com/security/data/fix/linux/alas2023-2026-3124.md) | Sep 28, 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 |
| Linux | libheif-debuginfo amzn 2023 | 1.23.4-1.amzn2023 | [ALAS2023-2026-3124](https://patchblox.com/security/data/fix/linux/alas2023-2026-3124.md) | Sep 28, 2026 |
| Linux | libheif-debugsource amzn 2023 | 1.23.4-1.amzn2023 | [ALAS2023-2026-3124](https://patchblox.com/security/data/fix/linux/alas2023-2026-3124.md) | Sep 28, 2026 |
| Linux | libheif-devel amzn 2023 | 1.23.4-1.amzn2023 | [ALAS2023-2026-3124](https://patchblox.com/security/data/fix/linux/alas2023-2026-3124.md) | Sep 28, 2026 |
| Linux | libheif-tools amzn 2023 | 1.23.4-1.amzn2023 | [ALAS2023-2026-3124](https://patchblox.com/security/data/fix/linux/alas2023-2026-3124.md) | Sep 28, 2026 |
| Linux | libheif-tools-debuginfo amzn 2023 | 1.23.4-1.amzn2023 | [ALAS2023-2026-3124](https://patchblox.com/security/data/fix/linux/alas2023-2026-3124.md) | Sep 28, 2026 |

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Data as of 2026-11-08T00:53:09Z 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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