CVE-2026-44663

The record

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.

Affected packages

Related vulnerabilities

• CVE-2026-45696 OpenEXR is the reference implementation and specification for the EXR image format… Also affects openexr
• CVE-2026-42217 OpenEXR provides the specification and reference implementation of the EXR file format… Also affects openexr
• CVE-2026-42216 OpenEXR provides the specification and reference implementation of the EXR file format… Also affects openexr
• CVE-2026-41142 OpenEXR provides the specification and reference implementation of the EXR file format… Also affects openexr
• CVE-2026-40250 OpenEXR provides the specification and reference implementation of the EXR file format… Also affects openexr
• CVE-2026-40244 OpenEXR provides the specification and reference implementation of the EXR file format… Also affects openexr
• CVE-2026-39886 OpenEXR provides the specification and reference implementation of the EXR file format… Also affects openexr
• CVE-2026-34589 OpenEXR provides the specification and reference implementation of the EXR file format… Also affects openexr