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.
- 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
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.
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.
Sources
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 and 4 more.