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

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2026-09-18 · updated 2026-09-29
Weakness: CWE-122

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.

Affected products

OpenImageIO Project OpenImageIO: before 3.0.21.0; from 3.1.0.0 through 3.1.16.0; 3.2.0.0-dev, 3.2.0.2-dev — fixed in 3.0.21.0

How to fix

Upgrade to a fixed version: OpenImageIO Project OpenImageIO 3.0.21.0. Check the vendor advisory for mitigations.

References

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