PT-2026-30658 · Academy Software Foundation · Openexr

Pwn2Woot

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Published

2026-04-06

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Updated

2026-04-06

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CVE-2026-34379

CVSS v3.1

7.1

High

AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:H
OpenEXR provides the specification and reference implementation of the EXR file format, an image storage format for the motion picture industry. From 3.2.0 to before 3.2.7, 3.3.9, and 3.4.9, a misaligned memory write vulnerability exists in LossyDctDecoder execute() in src/lib/OpenEXRCore/internal dwa decoder.h:749. When decoding a DWA or DWAB-compressed EXR file containing a FLOAT-type channel, the decoder performs an in-place HALF→FLOAT conversion by casting an unaligned uint8 t * row pointer to float * and writing through it. Because the row buffer may not be 4-byte aligned, this constitutes undefined behavior under the C standard and crashes immediately on architectures that enforce alignment (ARM, RISC-V, etc.). On x86 it is silently tolerated at runtime but remains exploitable via compiler optimizations that assume aligned access. This vulnerability is fixed in 3.2.7, 3.3.9, and 3.4.9.

Fix

Type Confusion

Memory Corruption

Incorrect Type Conversion or Cast

Weakness Enumeration

Related Identifiers

CVE-2026-34379

Affected Products

Openexr