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.
- 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
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.
Which versions are affected by CVE-2026-34545?
It affects 1 product.
Products include 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 OpenEXR Heap Overflow in Scanline Deep Data Parsing
- CVE-2026-41142 OpenEXR is Vulnerable to Integer overflow in ImageChannel::resize leads to heap OOB write via OpenEXRUtil public API
- CVE-2026-42216 OpenEXR: Out-of-bounds read in `IDManifest::init()` during prefix expansion
- CVE-2017-9111 OpenEXR invalid write
- CVE-2017-9113 Memory corruption in n/a
Sources
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 and 2 more.