OpenImageIO: Heap-buffer-overread in IffInput::readimg() when ZBUFFER flag is set (CVE-2026-59956) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-59956

OpenImageIO: Heap-buffer-overread in IffInput::readimg() when ZBUFFER flag is set

Answer in brief

CVE-2026-59956 records a Unknown severity vulnerability in OpenImageIO: Heap-buffer-overread in IffInput::readimg() when ZBUFFER flag is set. The current sources do not mark it as known exploited. The current feed maps AcademySoftwareFoundation/OpenImageIO (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 AcademySoftwareFoundation/OpenImageIO (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
AcademySoftwareFoundation/OpenImageIOgeneric	< 3.0.20.0 \|\| >= 3.1.0.0, < 3.1.15.0 \|\| >= 3.2.0.0-dev, < 3.2.0.3-beta1	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for AcademySoftwareFoundation/OpenImageIO.
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

OpenImageIO is a toolset for reading, writing, and manipulating image files of any image file format relevant to VFX / animation. Prior to 3.0.20.0, 3.1.15.0, and 3.2.0.3-beta1, An uncompressed 16-bit iff image with a z-buffer makes iffinput::readimg() allocate a temporary scanline from m_header.rgba_count but copy from it using m_header.pixel_bytes(), whose stride also includes z-buffer bytes. the oversized memcpy reads beyond the temporary heap buffer and copies adjacent memory into the output image, resulting in a crash or disclosure of adjacent heap data. The affected implementation is identified by src/iff.imageio/iffinput.cpp, IffInput::readimg(), m_header.rgba_count, and m_header.pixel_bytes(), which define the relevant source path, functions, state, and trigger. This issue is fixed in versions 3.0.20.0, 3.1.15.0, and 3.2.0.3-beta1.

Quoted source text, attributed separately from HOL analysis.