# CVE-2026-34545: OpenEXR: integer overflow lead to OOB in HTJ2K decoder

> An attacker can achieve remote code execution by providing a crafted EXR file with HTJ2K compression, exploiting an integer overflow in the decoder.

- **Severity:** High 8.4 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 1 Apr 2026
- **Updated:** 15 Jul 2026
- **Also known as:** BELL-CVE-2026-34545, DEBIAN-CVE-2026-34545, GHSA-ghfj-fx47-wg97, JLSEC-2026-147, ROOT-OS-DEBIAN-11-CVE-2026-34545, ROOT-OS-DEBIAN-12-CVE-2026-34545, ROOT-OS-DEBIAN-13-CVE-2026-34545, UBUNTU-CVE-2026-34545

## What is CVE-2026-34545?

CVE-2026-34545 is a high-severity vulnerability in Openexr Openexr, published on 1 Apr 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

OpenEXR provides the specification and reference implementation of the EXR file format, an image storage format for the motion picture industry. From version 3.4.0 to before version 3.4.7, an attacker providing a crafted .exr file with HTJ2K compression and a channel width of 32768 can write controlled data beyond the output heap buffer in any application that decodes EXR images. The write primitive is 2 bytes per overflow iteration or 4 bytes (by another path), repeating for each additional pixel past the overflow point. In this context, a heap write overflow can lead to remote code execution on systems. This issue has been patched in version 3.4.7.

Weakness: CWE-1284 (Improper Validation of Specified Quantity in Input), CWE-190 (Integer Overflow or Wraparound), CWE-122 (Heap-based Buffer Overflow)

## Which versions are affected by CVE-2026-34545?

It affects 1 product.


Products: Openexr Openexr.

## How do I fix CVE-2026-34545?

Upgrade to a fixed version.

## Is CVE-2026-34545 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-34545 exists.

## Other vulnerabilities in Openexr Openexr

- [CVE-2023-5841](https://insights.sbomify.com/CVE-2023-5841/): OpenEXR Heap Overflow in Scanline Deep Data Parsing (critical 9.1)
- [CVE-2026-41142](https://insights.sbomify.com/CVE-2026-41142/): OpenEXR is Vulnerable to Integer overflow in ImageChannel::resize leads to heap OOB write via OpenEXRUtil public API (high 8.8)
- [CVE-2026-42216](https://insights.sbomify.com/CVE-2026-42216/): OpenEXR: Out-of-bounds read in `IDManifest::init()` during prefix expansion (high 8.8)
- [CVE-2017-9111](https://insights.sbomify.com/CVE-2017-9111/): OpenEXR invalid write (high 8.8)
- [CVE-2017-9113](https://insights.sbomify.com/CVE-2017-9113/): Memory corruption in n/a (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-34545 and fix it if it is affected.

What it is: CVE-2026-34545 is a high-severity vulnerability in Openexr Openexr, published on 1 Apr 2026. It can only be exploited from the same machine or local network, 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-2026-34545 exists.

Affected product: Openexr 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-2026-34545/ (Markdown: https://insights.sbomify.com/CVE-2026-34545/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-34545
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-34545
- OSV: https://osv.dev/vulnerability/CVE-2026-34545

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-34545/
Summaries are generated and may contain mistakes; the official description above is the record.