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 3.3.5 and 3.4.0 through 3.4.2, while fuzzing openexr_exrcheck_fuzzer, Valgrind reports a conditional branch depending on uninitialized data inside generic_unpack. This indicates a use of uninitialized memory. The issue can result in undefined behavior and/or a potential crash/denial of service. Versions 3.3.6 and 3.4.3 fix the issue.
The code uses a variable that has not been initialized, leading to unpredictable or unintended results.