OpenEXR provides the specification and reference implementation of the EXR file format, an image storage format for the motion picture industry. In CompositeDeepScanLine::readPixels, per-pixel totals are accumulated in vector<unsigned int> total_sizes for attacker-controlled large counts across many parts, total_sizes[ptr] wraps modulo 2^32. overall_sample_count is then derived from wrapped totals and used in samples[channel].resize(overall_sample_count). Decode pointer setup/consumption proceeds with true sample counts, and write operations in core unpack (generic_unpack_deep_pointers) overrun the undersized composite sample buffer. This vulnerability is fixed in v3.2.6, v3.3.8, and v3.4.6.

OpenEXR provides the specification and reference implementation of the EXR file format, an image storage format for the motion picture industry. In versions 3.3.0 through 3.3.6 and 3.4.0 through 3.4.4, a heap-buffer-overflow (OOB read) occurs in the `istream_nonparallel_read` function in `ImfContextInit.cpp` when parsing a malformed EXR file through a memory-mapped `IStream`. A signed integer subtraction produces a negative value that is implicitly converted to `size_t`, resulting in a massive length being passed to `memcpy`. Versions 3.3.7 and 3.4.5 contain a patch.