AI description
CVE-2026-84383 describes an out-of-bounds write vulnerability found in `libheif`, a library responsible for decoding and encoding HEIF and AVIF image formats. This flaw affects versions of `libheif` from 1.22.0 up to, but not including, 1.23.2. The vulnerability arises when a maliciously crafted HEIF, HEIC, or AVIF file contains an item graph that utilizes nested `iden` and `auxl` references. Specifically, this crafted file can cause the `HeifPixelImage::transfer_channel_from_image_as()` function to append duplicate Alpha planes with varying bit depths. Subsequently, the `HeifPixelImage::scale_nearest_neighbor()` function, which allocates an 8-bit destination Alpha plane, attempts to write larger 10-bit or 12-bit Alpha components into this smaller 8-bit allocation. This action results in a heap out-of-bounds write. The issue is resolved in `libheif` version 1.23.2.
- Description
- libheif is a HEIF and AVIF file format decoder and encoder. From 1.22.0 until 1.23.2, a crafted HEIF, HEIC, or AVIF item graph using nested iden and auxl references can make HeifPixelImage::transfer_channel_from_image_as() append duplicate Alpha planes with different bit depths to m_storage. HeifPixelImage::scale_nearest_neighbor() in libheif/image/pixelimage.cc allocates the destination Alpha plane using the first plane's 8-bit depth, then iterates a later 10-bit or 12-bit Alpha component and writes uint16_t samples into the same 8-bit allocation. The output geometry controls the overflow extent and the encoded sample values control the data written, allowing a remote file processed by heif_decode_image() to cause a heap out-of-bounds write. This issue is fixed in version 1.23.2.
- Source
- security-advisories@github.com
- NVD status
- Deferred
CVSS 3.1
- Type
- Secondary
- Base score
- 9.8
- Impact score
- 5.9
- Exploitability score
- 3.9
- Vector string
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Severity
- CRITICAL
- security-advisories@github.com
- CWE-787
- Hype score
- Not currently trending