CVE-2026-34380— OpenEXR has a signed integer overflow (undefined behavior) in undo_pxr24_impl may allow bounds-check bypass in PXR24 decompression

OpenEXR has a signed integer overflow (undefined behavior) in undo_pxr24_impl may allow bounds-check bypass in PXR24 decompression

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 signed integer overflow exists in undo_pxr24_impl() in src/lib/OpenEXRCore/internal_pxr24.c at line 377. The expression (uint64_t)(w * 3) computes w * 3 as a signed 32-bit integer before casting to uint64_t. When w is large, this multiplication constitutes undefined behavior under the C standard. On tested builds (clang/gcc without sanitizers), two's-complement wraparound commonly occurs, and for specific values of w the wrapped result is a small positive integer, which may allow the subsequent bounds check to pass incorrectly. If the check is bypassed, the decoding loop proceeds to write pixel data through dout, potentially extending far beyond the allocated output buffer. This vulnerability is fixed in 3.2.7, 3.3.9, and 3.4.9.

CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:H

整数溢出或超界折返

OpenEXR 缓冲区错误漏洞

OpenEXR是Academy Software Foundation开源的一种高动态范围图像（HDR）文件格式的开放标准。 OpenEXR 3.2.0至3.2.7之前版本、3.3.9之前版本和3.4.9之前版本存在缓冲区错误漏洞，该漏洞源于整数溢出可能导致绕过边界检查，可能导致越界写入。

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