CVE-2026-84383criticalCWE-787

CVE-2026-84383: critical vulnerability in strukturag libheif

libheif: Heap buffer overflow in `scale_nearest_neighbor()` via duplicate Alpha planes from nested `iden`/`auxl` items

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48Vexday Risk Score

No sign of exploitation. It has a public proof of concept.

ssvc Attendcvss 9.8epss 0.7%
from disclosure to weapon11 days
Published on NVDSep 18
1st PoC+11d
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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Affected products
strukturag · libheif
⚠ Public resources, to assess the exposure of systems you control or are authorized to test. Test only with authorization.
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