CVE-2026-43909: OpenImageIO: Signed integer overflow in SwapRGBABytes loop index leads to out-of-bounds read/write in DPX ABGR decoder

Severity: high (CVSS 8.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% 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, a signed 32-bit integer overflow in the loop index expression i * 4 inside SwapRGBABytes() causes the function to compute a large negative pointer offset when processing kABGR DPX images with large dimensions. The immediate crash is an out-of-bounds read (the memcpy at line 45 reads from &input[i * 4] first), but the subsequent write operations at lines 46–49 target the same wrapped offset — making this a combined OOB read+write primitive. 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 3.1.4.0 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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