# CVE-2026-59186: OpenEXR: Heap out-of-bounds write in TiledRgbaInputFile via integer overflow on 32-bit (ILP32) builds

> A crafted EXR file triggers an integer overflow leading to heap out-of-bounds write in OpenEXR on 32-bit systems, potentially allowing code execution or crashes.

- **Severity:** High 7.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/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:** 25 Aug 2026
- **Updated:** 25 Aug 2026
- **Also known as:** AZL-97643, BELL-CVE-2026-59186, DEBIAN-CVE-2026-59186, ECHO-facf-fef3-54a9, GHSA-f667-c4wm-c8gq, MINI-jggv-xf45-w7w3, ROOT-OS-DEBIAN-11-CVE-2026-59186, ROOT-OS-DEBIAN-12-CVE-2026-59186, ROOT-OS-DEBIAN-13-CVE-2026-59186, UBUNTU-CVE-2026-59186

## What is CVE-2026-59186?

CVE-2026-59186 is a high-severity vulnerability in AcademySoftwareFoundation openexr, published on 25 Aug 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

OpenEXR is the reference implementation and specification for the EXR image format, widely used in the motion picture industry. In versions before 3.2.11, 3.3.0 through 3.3.12, and 3.4.0 through 3.4.13, a crafted tiled EXR can trigger a heap out-of-bounds write on 32-bit/ILP32 builds when read through the public TiledRgbaInputFile RGBA API. The file uses a small 40x40 dataWindow but a 65537x65537 tile size. On ILP32, the Array2D<Rgba> tile-conversion buffer size calculation overflows, allocates a much smaller heap buffer, and tile decode writes past that allocation. This issue is fixed in versions 3.2.11, 3.3.13, and 3.4.14.

Weakness: CWE-787 (Out-of-bounds Write), CWE-190 (Integer Overflow or Wraparound), CWE-122 (Heap-based Buffer Overflow)

## Which versions are affected by CVE-2026-59186?


## How do I fix CVE-2026-59186?

Upgrade to a fixed version.

## Is CVE-2026-59186 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-59186 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-59186 and fix it if it is affected.

What it is: CVE-2026-59186 is a high-severity vulnerability in AcademySoftwareFoundation openexr, published on 25 Aug 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-2026-59186 exists.

Affected product: AcademySoftwareFoundation openexr. 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-2026-59186/ (Markdown: https://insights.sbomify.com/CVE-2026-59186/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-59186
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-59186
- OSV: https://osv.dev/vulnerability/CVE-2026-59186

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-59186/
Summaries are generated and may contain mistakes; the official description above is the record.