CVE-2026-43996: OpenImageIO: Integer wraparound in bounds check of decode_pixel leads to out-of-bounds read in TGA paletted image decoder

Severity: medium (CVSS 5.5 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: 2026-05-14 · updated 2026-10-26
Weakness: CWE-125

Description

OpenImageIO is a toolset for reading, writing, and manipulating image files of any image file format relevant to VFX / animation. Prior to 3.0.18.0 and 3.1.13.0, the bounds check in TGAInput::decode_pixel computes k + palbytespp as unsigned 32-bit arithmetic. When k = 0xFFFFFFFC and palbytespp = 4, the addition wraps to 0, which compares less than palette_alloc_size and passes the check. The subsequent palette access uses the unwrapped k (0xFFFFFFFC) as the index, reading ~4 GB past the start of the palette buffer — SEGV. This vulnerability is fixed in 3.0.18.0 and 3.1.13.0.

Affected products

OpenImageIO Project OpenImageIO: before 3.0.18.0; from 3.1.0.0 before 3.1.13.0; 3.2.0.0-dev, 3.2.0.2-dev — fixed in 3.0.18.0, 3.1.13.0

How to fix

Upgrade to a fixed version: OpenImageIO Project OpenImageIO 3.0.18.0, 3.1.13.0. Check the vendor advisory for mitigations.

References

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