CVE-2025-59732 in FFmpeg
Summary
by MITRE • 10/06/2025
When decoding an OpenEXR file that uses DWAA or DWAB compression, there's an implicit assumption that the height and width are divisible by 8.
If the height or width of the image is not divisible by 8, the copy loops at [0] and [1] will continue to write until the next multiple of 8.
The buffer td->uncompressed_data is allocated in decode_block based on the precise height and width of the image, so the "rounded-up" multiple of 8 in the copy loop can exceed the buffer bounds, and the write block starting at [2] can corrupt following heap memory.
We recommend upgrading to version 8.0 or beyond.
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Analysis
by VulDB Data Team • 06/21/2026
The vulnerability identified as CVE-2025-59732 represents a critical buffer overflow condition within OpenEXR file processing libraries that utilize DWAA or DWAB compression algorithms. This flaw manifests when decompressing image files where the dimensions do not conform to multiples of eight pixels, creating a scenario where memory corruption occurs during the decompression process. The issue stems from an implicit assumption in the codebase that all image dimensions must be divisible by eight, a constraint that does not hold true for all valid OpenEXR files, particularly those with arbitrary dimensions that are commonly encountered in professional imaging workflows.
The technical implementation of this vulnerability occurs within the decode_block function where memory allocation for the uncompressed_data buffer is calculated based on the exact height and width parameters of the input image. However, the decompression loops that process the data employ a rounding mechanism that assumes eight-pixel alignment for copying operations, leading to a scenario where the loop iterations continue beyond the allocated buffer boundaries. This misalignment between buffer allocation and loop execution creates a classic heap-based buffer overflow condition where subsequent memory writes can overwrite adjacent heap allocations, potentially leading to arbitrary code execution or system instability.
The operational impact of this vulnerability extends beyond simple memory corruption, as it affects the fundamental reliability of image processing systems that depend on OpenEXR format support. Attackers could exploit this vulnerability by crafting malicious OpenEXR files with dimensions that are not divisible by eight, causing applications to crash or behave unpredictably when processing these files. The vulnerability is particularly concerning in professional environments where image processing pipelines handle large volumes of data from multiple sources, as it could enable denial-of-service attacks or potentially provide a foothold for more sophisticated exploitation techniques. The flaw affects systems across multiple platforms and applications that utilize the affected OpenEXR library versions, making it a widespread concern for digital content creators and processing environments.
From a cybersecurity perspective, this vulnerability aligns with CWE-121, heap-based buffer overflow, and demonstrates characteristics consistent with ATT&CK technique T1059.007 for execution through legitimate user interfaces. The vulnerability's exploitation requires minimal prerequisites, as it only requires the ability to process OpenEXR files, making it particularly dangerous in automated processing environments. Organizations should prioritize immediate remediation by upgrading to version 8.0 or later, which includes proper bounds checking and alignment handling for image dimensions that do not conform to the eight-pixel boundary assumption. Additionally, implementing input validation measures and restricting OpenEXR file processing to trusted sources can provide additional defense-in-depth layers against potential exploitation attempts.