# CVE-2026-34378: openexr: OpenEXR provides the specification and reference implementation of the EXR file format, an image storage format for t...

CVE-2026-34378 is fixed in 6 products on 1 platform, first by DEBIAN-CVE-2026-34378, released April 6, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-34378
- Priority: Routine
- CVSS: 6.5 (medium)
- EPSS: 0.0027
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Apr 6, 2026

## Description

OpenEXR provides the specification and reference implementation of the EXR file format, an image storage format for the motion picture industry. From 3.4.0 to before 3.4.9, a missing bounds check on the dataWindow attribute in EXR file headers allows an attacker to trigger a signed integer overflow in generic_unpack(). By setting dataWindow.min.x to a large negative value, OpenEXRCore computes an enormous image width, which is later used in a signed integer multiplication that overflows, causing the process to terminate with SIGILL via UBSan. This vulnerability is fixed in 3.4.9.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | openexr Debian 14 | 3.4.14-0.1 | [DEBIAN-CVE-2026-34378](https://patchblox.com/security/data/fix/linux/debian-cve-2026-34378.md) | Apr 6, 2026 |
| Linux | openexr amzn 2023 | 3.1.5-1.amzn2023.0.9 | [ALAS2023-2026-1612](https://patchblox.com/security/data/fix/linux/alas2023-2026-1612.md) | Apr 27, 2026 |
| Linux | openexr-debuginfo amzn 2023 | 3.1.5-1.amzn2023.0.9 | [ALAS2023-2026-1612](https://patchblox.com/security/data/fix/linux/alas2023-2026-1612.md) | Apr 27, 2026 |
| Linux | openexr-debugsource amzn 2023 | 3.1.5-1.amzn2023.0.9 | [ALAS2023-2026-1612](https://patchblox.com/security/data/fix/linux/alas2023-2026-1612.md) | Apr 27, 2026 |
| Linux | openexr-devel amzn 2023 | 3.1.5-1.amzn2023.0.9 | [ALAS2023-2026-1612](https://patchblox.com/security/data/fix/linux/alas2023-2026-1612.md) | Apr 27, 2026 |
| Linux | openexr-libs amzn 2023 | 3.1.5-1.amzn2023.0.9 | [ALAS2023-2026-1612](https://patchblox.com/security/data/fix/linux/alas2023-2026-1612.md) | Apr 27, 2026 |
| Linux | openexr-libs-debuginfo amzn 2023 | 3.1.5-1.amzn2023.0.9 | [ALAS2023-2026-1612](https://patchblox.com/security/data/fix/linux/alas2023-2026-1612.md) | Apr 27, 2026 |

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Data as of 2026-11-08T19:12:23Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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