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Back to active CVEs
Critical · CVSS 9.8CVE-2026-84383

libheif: Heap buffer overflow in `scale_nearest_neighbor()` via duplicate Alpha planes from nested `iden`/`auxl` itemsCVE-2026-84383

Answer in brief

CVE-2026-84383 records a Critical severity (CVSS 9.8) vulnerability in libheif: Heap buffer overflow in `scale_nearest_neighbor()` via duplicate Alpha planes from nested `iden`/`auxl` items. The current sources do not mark it as known exploited. The current feed maps strukturag/libheif (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 18, 2026Updated Sep 18, 2026Source checked Nov 2, 2026First seen by HOL Sep 18, 2026Material review Sep 18, 2026
Upstream Advisory

Key facts

Risk
Critical · CVSS 9.8
Exploitation
Not marked as known exploited
Affected software
1 mapped package or product
Fix availability
Available

Why this deserves its current priority

CVSS is 9.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps strukturag/libheif (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
PackageAffected rangeFixed version
strukturag/libheifgeneric>=1.22.0 <1.23.21.23.2

Recommended response

  1. 1Check inventory. Check lockfiles and deployed manifests for strukturag/libheif.
  2. 2Review the reported fix. Update strukturag/libheif to 1.23.2 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

  1. Published upstream

    Sep 18, 2026

    Evidence: source:cvelist:source_dates:source-dates:record

  2. Source modified

    Sep 18, 2026

    Evidence: source:cvelist:source_dates:source-dates:record

  3. First seen by HOL

    Sep 18, 2026

Sources and claim methodology

  • GitHub security advisorygithub.com
  • GitHub security advisorygithub.com
  • GitHub security advisorygithub.com
Upstream source 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.

Quoted source text, attributed separately from HOL analysis.

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  • Amlogic DroidLogic SubTitleService Out-of-Bounds Write via VobSub SET_CONTRAlso CWE-787
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  • psqlODBC stack buffer overflow copying ctid and oid values for updatable cursorsAlso CWE-787

Record context

Vulnerability class
Memory Corruption
EPSS
Not reported
CWE IDs
CWE-787
Source
CVE List V5
Source checked
Nov 2, 2026
References
3 linked sources
Open source record