CVE-2025-59733: ffmpeg Out-of-bounds Write

Vulnerability summary

CVE-2025-59733 is a high (CVSS 8.7) Out-of-bounds Write vulnerability in ffmpeg. EPSS estimates a 0.18% chance of exploitation in the next 30 days, higher than 7.6% of scored vulnerabilities.

Timeline

1. 06-10-2025
   PublishedVulnerability first disclosed.
2. 26-02-2026
   Last modifiedVulnerability information updated.

Description

When decoding an OpenEXR file that uses DWAA or DWAB compression, there's an implicit assumption that all image channels have the same pixel type (and size), and that if there are four channels, the first four are "B", "G", "R" and "A". The channel parsing code can be found in decode_header. The buffer td->uncompressed_data is allocated in decode_block based on the xsize, ysize and computed current_channel_offset. The function dwa_uncompress then assumes at [5] that if there are 4 channels, these are "B", "G", "R" and "A", and in the calculations at [6] and [7] that all channels are of the same type, which matches the type of the main color channels. If we set the main color channels to a 4-byte type and add duplicate or unknown channels of the 2-byte EXR_HALF type, then the addition at [7] will increment the pointer by 4-bytes * xsize * nb_channels, which will exceed the allocated buffer. We recommend upgrading to version 8.0 or beyond.

• CWE-787Out-of-bounds WriteThe product writes data past the end, or before the beginning, of the intended buffer.