Reference page — cumulative record through Saturday, October 3, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2026-59956

CVE-2026-59956MEDIUM

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

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   L   L   N   R  U  L  N  H    6.1   .0020    9.1     —

AFFECTED
  Product      Versions      Fixed
  OpenImageIO  < 3.0.20.0 –  —

TIMELINE
  Jul 7   Reserved by GitHub_M
  Sep 18  Published (CNA: GitHub_M)
  Sep 29  EXPLOIT PUBLISHED — CVE-2026-59956 (AcademySoftwareFoundation OpenImageIO). Public exploit reference added.

CWE-125 · CNA: GitHub_M · CVSS v3.1 · 5 references · NVD status: Analyzed

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.

Lifecycle

Complete event history — 3 events, chronological
Date	Event	Detail
July 7, 2026	Reserved	Reserved by GitHub_M
September 18, 2026	Published	Published (CNA: GitHub_M)
September 29, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2026-59956 (AcademySoftwareFoundation OpenImageIO). Public exploit reference added.

Affected

Affected products and packages — 1 row
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
AcademySoftwareFoundation	OpenImageIO	—	< 3.0.20.0	—

Weaknesses

CWE-125

References (5)

https://github.com/AcademySoftwareFoundation/OpenImageIO/commit/f01bd16764b2a06f372899e3e302280a7f9c8c02 [Patch]
https://github.com/AcademySoftwareFoundation/OpenImageIO/pull/5251 [Issue Tracking, Patch]
https://github.com/AcademySoftwareFoundation/OpenImageIO/releases/tag/v3.0.20.0 [Release Notes]
https://github.com/AcademySoftwareFoundation/OpenImageIO/releases/tag/v3.1.15.0 [Release Notes]
https://github.com/AcademySoftwareFoundation/OpenImageIO/security/advisories/GHSA-hjfv-gvxc-qgvh [Exploit, Vendor Advisory]

Authoritative record: CVE-2026-59956 at cve.org

Vendors: academysoftwarefoundation

Weaknesses: CWE-125

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-59956 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Saturday, October 3, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.