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

> A signed integer overflow in OpenImageIO's DPX decoder allows out-of-bounds read and write operations, potentially leading to code execution or crashes.

- **Severity:** High 8.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 14 May 2026
- **Updated:** 14 May 2026
- **Also known as:** DEBIAN-CVE-2026-43909, GHSA-g267-j53j-5258, UBUNTU-CVE-2026-43909

## What is CVE-2026-43909?

CVE-2026-43909 is a high-severity vulnerability in Openimageio Openimageio, published on 14 May 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official 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.

Weakness: CWE-787 (Out-of-bounds Write), CWE-190 (Integer Overflow or Wraparound), CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2026-43909?

It affects 1 product.


Products: Openimageio Openimageio.

## How do I fix CVE-2026-43909?

Upgrade to a fixed version.

## Is CVE-2026-43909 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-43909 exists.

## Other vulnerabilities in Openimageio Openimageio

- [CVE-2024-55192](https://insights.sbomify.com/CVE-2024-55192/): Memory corruption in n/a (critical 9.8)
- [CVE-2024-55194](https://insights.sbomify.com/CVE-2024-55194/): Memory corruption in n/a (critical 9.8)
- [CVE-2023-42299](https://insights.sbomify.com/CVE-2023-42299/): Memory corruption in n/a (critical 9.8)
- [CVE-2022-38143](https://insights.sbomify.com/CVE-2022-38143/): Memory corruption in OpenImageIO (critical 9.8)
- [CVE-2026-43908](https://insights.sbomify.com/CVE-2026-43908/): OpenImageIO: Signed integer overflow in ConvertCbYCrYToRGB leads to heap out-of-bounds write in DPX 4:2:2 decoder (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-43909 and fix it if it is affected.

What it is: CVE-2026-43909 is a high-severity vulnerability in Openimageio Openimageio, published on 14 May 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-43909 exists.

Affected product: Openimageio Openimageio. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-43909/ (Markdown: https://insights.sbomify.com/CVE-2026-43909/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-43909
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-43909
- OSV: https://osv.dev/vulnerability/CVE-2026-43909

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-43909/
Summaries are generated and may contain mistakes; the official description above is the record.