CVE-2026-44663 OpenEXR: Integer overflow in the HTJ2K decoder leads to heap-buffer-overflow
An integer overflow in the HTJ2K decoder allows attackers to trigger a heap-buffer overflow via crafted EXR files, potentially leading to code execution or crashes.
- 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-2026-44663?
CVE-2026-44663 is a medium-severity vulnerability in Openexr Openexr, published on 18 Jun 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 is the reference implementation and specification for the EXR image format, widely used in the motion picture industry. In versions 3.4.0 through 3.4.11, an integer overflow in ht_undo_impl() in src/lib/OpenEXRCore/internal_ht.cpp leads to a heap-buffer overflow when decoding a crafted HTJ2K-compressed EXR file. decode->channels[i].width (int32_t) is multiplied by bytes_per_element in 32-bit signed arithmetic. With large widths (e.g., >= 536870912 for FLOAT data), this overflows, producing a corrupted offset that is later used for pointer arithmetic and can cause a heap out-of-bounds write. The same unchecked multiplication pattern appears in two other HTJ2K paths (bytes-per-line accumulation and pixel-line pointer advancement). As with related CVE-2026-34378 through CVE-2026-34589 fixes in other codecs, validating only after the multiplication is too late because the value may already be overflowed. This issue has been fixed in version 3.4.12.
Which versions are affected by CVE-2026-44663?
It affects 1 product.
Products include Openexr Openexr.
How do I fix CVE-2026-44663?
Upgrade to a fixed version.
Is CVE-2026-44663 being exploited?
There is no known exploitation of CVE-2026-44663 in the wild and no public exploit code.
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-2026-44663, DEBIAN-CVE-2026-44663, GHSA-777r-f9x8-7r84, JLSEC-2026-812, UBUNTU-CVE-2026-44663.