OpenEXR versions prior to 3.2.7, 3.3.9, and 3.4.9 contain a vulnerability in LossyDctDecoder_execute() where an unaligned memory write occurs during HALF to FLOAT conversion of DWA/DWAB-compressed EXR files. The decoder casts an unaligned uint8_t * row pointer to float * and writes through it, causing undefined behavior and potential crashes on architectures like ARM and RISC-V that enforce alignment. On x86, this is tolerated at runtime but can be exploited due to compiler assumptions about alignment. This vulnerability is addressed by fixes in versions 3.2.7, 3.3.9, and 3.4.9.

This vulnerability can cause application crashes (denial of service) on architectures enforcing strict memory alignment (e.g., ARM, RISC-V) when processing crafted EXR files. On x86 architectures, it may lead to undefined behavior exploitable via compiler optimizations, potentially impacting application stability or security. There is no direct evidence of confidentiality or integrity compromise, but availability is affected due to crashes.

Fixed versions 3.2.7, 3.3.9, and 3.4.9 of openexr address this vulnerability. Users should upgrade to one of these versions to remediate the issue. No vendor advisory indicates alternative mitigations or that no action is required. Patch status is confirmed by the vendor advisory. No cloud service remediation applies as this is a library.