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-2026-63638

CVE-2026-63638HIGH

AcademySoftwareFoundation OpenImageIO — OpenImageIO: Cineon invalid bit depth heap out-of-bounds write

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   N   L   N   R  U  L  H  H    8.3   .0046   38.0     —

AFFECTED
  Product      Versions      Fixed
  OpenImageIO  < 3.0.21.0 –  —

TIMELINE
  Jul 17  Reserved by GitHub_M
  Sep 18  Published (CNA: GitHub_M)
  Sep 29  EXPLOIT PUBLISHED — CVE-2026-63638 (AcademySoftwareFoundation OpenImageIO). Public exploit reference added.

CWE-787 · 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 3.0.21.0, 3.1.16.0, and 3.2.0.3-beta1, A crafted cineon image can declare unsupported component bit depth 26. cineoninput::open() maps it to a 32-bit imagespec, but libcineon maps the unsupported depth to an 8-byte value, so cineoninput::read_native_scanline() causes attacker-controlled data to be written beyond the 4-byte-per-pixel caller buffer, resulting in a heap out-of-bounds write and memory corruption. The affected implementation is identified by src/cineon.imageio/cineoninput.cpp, CineonInput::open(), CineonInput::read_native_scanline(), ComponentDataSize(), bit depth 26, and ImageSpec, which define the relevant source path, functions, state, and trigger. This issue is fixed in versions 3.0.21.0, 3.1.16.0, and 3.2.0.3-beta1.

Lifecycle

Complete event history — 3 events, chronological
Date	Event	Detail
July 17, 2026	Reserved	Reserved by GitHub_M
September 18, 2026	Published	Published (CNA: GitHub_M)
September 29, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2026-63638 (AcademySoftwareFoundation OpenImageIO). Public exploit reference added.

Affected

Affected products and packages — 1 row
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
AcademySoftwareFoundation	OpenImageIO	—	< 3.0.21.0	—

Weaknesses

CWE-787

References (5)

https://github.com/AcademySoftwareFoundation/OpenImageIO/commit/6f2b2e85b3b3933ccc5a46303d5535f99bfa39fb [Patch]
https://github.com/AcademySoftwareFoundation/OpenImageIO/pull/5283 [Issue Tracking, Patch]
https://github.com/AcademySoftwareFoundation/OpenImageIO/releases/tag/v3.0.21.0 [Release Notes]
https://github.com/AcademySoftwareFoundation/OpenImageIO/releases/tag/v3.1.16.0 [Release Notes]
https://github.com/AcademySoftwareFoundation/OpenImageIO/security/advisories/GHSA-9hxv-jvgr-3x8g [Exploit, Mitigation, Vendor Advisory]

Authoritative record: CVE-2026-63638 at cve.org

Vendors: academysoftwarefoundation

Weaknesses: CWE-787

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-63638 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.