libheif uncompressed tiled image encoding allows out-of-bounds write (CVE-2026-84444) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-84444

libheif uncompressed tiled image encoding allows out-of-bounds write

Answer in brief

CVE-2026-84444 records a Unknown severity vulnerability in libheif uncompressed tiled image encoding allows out-of-bounds write. 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 Sep 18, 2026First seen by HOL Sep 18, 2026Material review Sep 18, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Not reported

Why this deserves its current priority

A CVSS score is not reported in the current record. 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
Package	Affected range	Fixed version
strukturag/libheifgeneric	< 1.23.2	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for strukturag/libheif.
Review the reported fix. Monitor this advisory for an available fix and review any installs of the affected package.

Evidence timeline and material changes

Published upstream
Sep 18, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 18, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 18, 2026

Sources and claim methodology

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.